Internet Engineering Task Force Georgios Karagiannis
Internet-Draft University of Twente
Intended status: Experimental Anurag Bhargava
Expires: April 21, 2014 Cisco Systems, Inc.
October 21, 2013
Generic Aggregation of Resource ReSerVation Protocol (RSVP)
for IPv4 And IPv6 Reservations over PCN domains
draft-ietf-tsvwg-rsvp-pcn-07
Abstract
This document specifies extensions to Generic Aggregated RSVP
[RFC4860] for support of the PCN Controlled Load (CL) and Single
Marking (SM) edge behaviors over a Diffserv cloud using Pre-
Congestion Notification.
Status of this Memo
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This Internet-Draft will expire on April 21, 2014.
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Copyright Notice
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Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Objective . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Overview and Motivation . . . . . . . . . . . . . . . . . . . 4
1.3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4. Organization of This Document . . . . . . . . . . . . . . . . 11
2. Overview of RSVP extensions and Operations . . . . . . . . . . . 11
2.1. Overview of RSVP Aggregation Procedures in PCN domains . . . . . 11
2.2. PCN Marking and encoding and transport of pre-congestion
Information . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.3. Traffic Classification Within The Aggregation Region . . . . . . 13
2.4. Deaggregator (PCN-egress-node) Determination . . . . . . . . . . 13
2.5. Mapping E2E Reservations Onto Aggregate Reservations . . . . . . 14
2.6 Size of Aggregate Reservations . . . . . . . . . . . . . . . . . 15
2.7. E2E Path ADSPEC update . . . . . . . . . . . . . . . . . . . . . 15
2.8. Intra-domain Routes . . . . . . . . . . . . . . . . . . . . . . .15
2.9. Inter-domain Routes . . . . . . . . . . . . . . . . . . . . . . 15
2.10. Reservations for Multicast Sessions . . . . . . . . . . . . . . 15
2.11. Multi-level Aggregation . . . . . . . . . . . . . . . . . . . . 15
2.12. Reliability Issues . . . . . . . . . . . . . . . . . . . . . . 15
2.13. Message Integrity and Node Authentication . . . . . . . . . . 16
3. Elements of Procedure . . . . . . . . . . . . . . . . . . . . . . 16
3.1. Receipt of E2E Path Message By PCN-ingress-node
(aggregating router) . . . . . . . . . . . . . . . . . . . . . . 17
3.2. Handling Of E2E Path Message By Interior Routers . . . . . . . 17
3.3. Receipt of E2E Path Message By PCN-egress-node
(deaggregating router) . . . . . . . . . . . . . . . . . . . . . 17
3.4. Initiation of new Aggregate Path Message By PCN-ingress-node
(Aggregating Router) . . . . . . . . . . . . . . . . . . . . . 18
3.5. Handling Of new Aggregate Path Message By Interior Routers . . 18
3.6. Handling of E2E Resv Message by Deaggregating Router . . . . . 18
3.7. Handling Of E2E Resv Message By Interior Routers . . . . . . . 18
3.8. Initiation of New Aggregate Resv Message By Deaggregating Router 19
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3.9. Handling of Aggregate Resv Message by Interior Routers . . . . 18
3.10. Handling of E2E Resv Message by Aggregating Router . . . . . . 19
3.11. Handling of Aggregated Resv Message by Aggregating Router . . 19
3.12. Removal of E2E Reservation . . . . . . . . . . . . . . . . . . 20
3.13. Removal of Aggregate Reservation . . . . . . . . . . . . . . . 20
3.14. Handling of Data On Reserved E2E Flow by Aggregating Router . 20
3.15. Procedures for Multicast Sessions . . . . . . . . . . . . . . 21
3.16. Misconfiguration of PCN node . . . . . . . . . . . . . . . . 21
4. Protocol Elements . . . . . . . . . . . . . . . . . . . . . . . . 21
4.1 PCN object . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5. Security Considerations . . . . . . . . . . . . . . . . . . . . . 26
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 26
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 26
8. Normative References . . . . . . . . . . . . . . . . . . . . . . 27
9. Informative References . . . . . . . . . . . . . . . . . . . . . 27
10. Appendix A: Example Signaling Flow . . . . . . . . . . . . . . . 28
11. Authors' Address . . . . . . . . . . . . . . . . . . . . . . . . 31
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1. Introduction
1.1 Objective
Pre-Congestion Notification (PCN) can support the quality of service
(QoS) of inelastic flows within a Diffserv domain in a simple,
scalable, and robust fashion. Two mechanisms are used: admission
control and flow termination. Admission control is used to decide
whether to admit or block a new flow request, while flow termination
is used in abnormal circumstances to decide whether to terminate some
of the existing flows. To support these two features, the overall
rate of PCN-traffic is metered on every link in the domain, and PCN-
packets are appropriately marked when certain configured rates are
exceeded. These configured rates are below the rate of the link,
thus providing notification to boundary nodes about overloads before
any congestion occurs (hence "pre-congestion" notification). The
PCN-egress-nodes measure the rates of differently marked PCN traffic
in periodic intervals and report these rates to the Decision Points
for admission control and flow termination; the Decision Points use
these rates to make decisions. The Decision Points may be collocated
with the PCN-ingress-nodes, or their function may be implemented in a
centralized node. For more details see [RFC5559], [RFC6661], and
[RFC6662].
The main objective of this document is to specify the signaling
protocol that can be used within a Pre-Congestion Notification (PCN)
domain to carry reports from a PCN-egress-node to a PCN Decision
point, considering that the PCN decision Point and PCN-ingress-node
are collocated.
If the PCN decision point is not collocated with the PCN-ingress-node
then additional signaling procedures are required that are out of
the scope of this document. Moreover, as mentioned above this
architecture conforms with PBAC (Policy-Based Admission Control),
when decision point is located in a centralized node [RFC2753].
Several signaling protocols can be used to carry reports from a PCN-
egress-node to a PCN-ingress-nodes. However, since both PCN-egress-
node and PCN-ingress-nodes are located on the data path, a signaling
protocol that follows the same path as the data path, like RSVP
(Resource Reservation Protocol), is more suited for this purpose. In
particular, this document specifies extensions to Generic
Aggregated RSVP [RFC4860] for support of the PCN Controlled Load (CL)
and Single Marking (SM) edge behaviors over a Diffserv cloud using
Pre-Congestion Notification.
1.2 Overview and Motivation
Two main Quality of Service (QoS) architectures have been specified
by the IETF. These are the Integrated Services (Intserv) [RFC1633]
architecture and the Differentiated Services (DiffServ) architecture
([RFC2475]).
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Intserv provides methods for the delivery of end-to-end Quality of
Service (QoS) to applications over heterogeneous networks. One of the
QoS signaling protocols used by the Intserv architecture is the
Resource reServation Protocol (RSVP) [RFC2205], which can be used by
applications to request per-flow resources from the network. These
RSVP requests can be admitted or rejected by the network.
Applications can express their quantifiable resource requirements
using Intserv parameters as defined in [RFC2211] and [RFC2212]. The
Controlled Load (CL) service [RFC2211] is a quality of service (QoS)
closely approximating the QoS that the same flow would receive from a
lightly loaded network element. The CL service is useful for
inelastic flows such as those used for real-time media.
The DiffServ architecture can support the differentiated treatment of
packets in very large scale environments. While Intserv and RSVP
classify packets per-flow, Diffserv networks classify packets into
one of a small number of aggregated flows or "classes", based on the
Diffserv codepoint (DSCP) in the packet IP header. At each Diffserv
router, packets are subjected to a "per-hop behavior" (PHB), which is
invoked by the DSCP. The primary benefit of Diffserv is its
scalability, since the need for per-flow state and per-flow
processing, is eliminated.
However, DiffServ does not include any mechanism for communication
between applications and the network. Several solutions have been
specified to solve this issue. One of these solutions is Intserv over
Diffserv [RFC2998] including resource-based admission control (RBAC),
PBAC, assistance in traffic identification/classification, and
traffic conditioning. Intserv over Diffserv can operate over a
statically provisioned Diffserv region or RSVP aware. When it is RSVP
aware, several mechanisms may be used to support dynamic provisioning
and topology-aware admission control, including aggregate RSVP
reservations, per-flow RSVP, or a bandwidth broker. [RFC3175]
specifies aggregation of Resource ReSerVation Protocol (RSVP) end-to-
end reservations over aggregate RSVP reservations. In [RFC3175] the
RSVP aggregated reservation is characterized by a RSVP SESSION object
using the 3-tuple <source IP address, destination IP address,
Diffserv Code Point>.
Several scenarios require the use of multiple generic aggregate
reservations that are established for a given PHB from a given source
IP address to a given destination IP address, see [SIG-NESTED],
[RFC4860]. For example, multiple generic aggregate reservations
can be applied in the situation that multiple e2e reservations using
different preemption priorities need to be aggregated through a PCN-
domain using the same PHB. By using multiple aggregate reservations
for the same PHB allows enforcement of the different preemption
priorities within the aggregation region. This allows more efficient
management of the Diffserv resources, and in periods of resource
shortage, this allows sustainment of a larger number of E2E
reservations with higher preemption priorities. In particular,
[SIG-NESTED] discusses in detail how end-to-end RSVP reservations can
be established in a nested VPN environment through RSVP aggregation.
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[RFC4860] provides generic aggregate reservations by extending
[RFC3175] to support multiple aggregate reservations for the same
source IP address, destination IP address, and PHB (or set of PHBs).
In particular, multiple such generic aggregate reservations can be
established for a given PHB from a given source IP address to a given
destination IP address. This is achieved by adding the concept of a
Virtual Destination Port and of an Extended Virtual Destination Port
in the RSVP SESSION object. In addition to this, the RSVP SESSION
object for generic aggregate reservations uses the PHB Identification
Code (PHB-ID) defined in [RFC3140], instead of using the Diffserv
Code Point (DSCP) used in [RFC3175]. The PHB-ID is used to identify
the PHB, or set of PHBs, from which the Diffserv resources are to be
reserved.
The RSVP like signaling protocol required to carry reports from a
PCN-egress-node to a PCN-ingress-node needs to follow the PCN
signaling requirements defined in [RFC6663]. In addition to
that the signaling protocol functionality supported by the PCN-
ingress-nodes and PCN-egress-nodes needs to maintain logical
aggregate constructs (i.e. ingress-egress-aggregate state) and be
able to map e2e reservations to these aggregate constructs. Moreover,
no actual reservation state is needed to be maintained inside the PCN
domain, i.e., the PCN-interior-nodes are not maintaining any
reservation state.
This can be accomplished by two possible approaches:
Approach (1):
o) adapting the RFC 4860 aggregation procedures to fit the PCN
requirements with as little change as possible over the RFC 4860
functionality
o) hence performing aggregate RSVP signaling (even if it is to be
ignored by PCN interior nodes)
o) using this aggregate RSVP signaling procedures to carry PCN
information from PCN-egress-node to the PCN-ingress-node.
Approach (2):
o) adapting the RFC 4860 aggregation procedures to fit the PCN
requirements with more significant changes over RFC4860 (i.e.
the aspect of the procedures that have to do with maintaining
aggregate states and to do with mapping the e2e reservations to
aggregate constructs are kept, but the procedures that have to
do with the aggregate RSVP signaling and aggregate reservation
establishment/maintenance are dropped).
o) hence not performing aggregate RSVP signaling
o) piggy-backing of the PCN information inside the e2e RSVP
signaling.
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Both approaches are probably viable, however, since the RFC 4860
operations have been thoroughly studied and implemented, it can be
considered that the RFC 4860 solution can better deal with the more
challenging situations (rerouting in the PCN domain, failure of an
PCN-ingress-node, failure of an PCN-egress-node, rerouting towards a
different edge, etc.). This is the reason for choosing Approach (1)
for the specification of the signaling protocol used to carry
PCN information from the PCN-egress-node to the PCN-ingress-node.
In particular, this document specifies extensions to Generic
Aggregated RSVP [RFC4860] for support of the PCN Controlled Load (CL)
and Single Marking (SM) edge behaviors over a Diffserv cloud using
Pre-Congestion Notification.
This document follows the PCN signaling requirements defined in
[RFC6663] and specifies extensions to Generic Aggregated RSVP
[RFC4860] for support of PCN edge behaviors as specified in
[RFC6661] and [RFC6662]. Moreover, this document specifies how RSVP
aggregation can be used to setup and maintain: (1) Ingress Egress
Aggregate (IEA) states at Ingress and Egress nodes and (2) generic
aggregation of RSVP end-to-end RSVP reservations over PCN (Congestion
and Pre-Congestion Notification) domains.
To comply with this specification, PCN-nodes MUST be able to
support the functionality specified in [RFC5670], [RFC5559],
[RFC6660], [RFC6661], [RFC6662]. Furthermore, the PCN-boundary-nodes
MUST support the RSVP generic aggregated reservation procedures
specified in [RFC4860] which are augmented with procedures specified
in this document.
1.3. Terminology
This document uses terms defined in [RFC4860], [RFC3175], [RFC5559],
[RFC5670], [RFC6661], [RFC6662].
For readability, a number of definitions from [RFC3175] as well as
definitions for terms used in [RFC5559], [RFC6661], and [RFC6662] are
provided here, where some of them are augmented with new meanings:
Aggregator This is the process in (or associated with) the
router at the ingress edge of the aggregation region
(with respect to the end-to-end RSVP reservation)
and behaving in accordance with [RFC4860]. In this
document, it is also the PCN-ingress-node and the
decision point. It is important to notice that in
the context of this document the Aggregator MUST be
able to determine the Deaggregator using the
procedures specified in Section 4 of [RFC4860] and
in Section 1.4.2 of [RFC3175].
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Deaggregator This is the process in (or associated with) the
router at the egress edge of the aggregation region
(with respect to the end-to-end RSVP reservation)
and behaving in accordance with [RFC4860]. In this
document, it is also the PCN-egress-node.
E2E (or e2e) end to end
E2E Reservation This is an RSVP reservation such that:
(i) corresponding RSVP Path messages are initiated
upstream of the Aggregator and terminated
downstream of the Deaggregator, and
(ii) corresponding RSVP Resv messages are initiated
downstream of the Deaggregator and terminated
upstream of the Aggregator, and
(iii) this RSVP reservation is aggregated over an
Ingress Egress Aggregate (IEA) between the
Aggregator and Deaggregator.
An E2E RSVP reservation may be a per-flow
reservation, which in this document is only
maintained at the PCN-ingress-node and PCN-egress-
node. Alternatively, the E2E reservation may itself
be an aggregate reservation of various types (e.g.,
Aggregate IP reservation, Aggregate IPsec
reservation, see [RFC4860]). As per regular RSVP
operations, E2E RSVP reservations are
unidirectional.
PHB-ID (Per Hop Behavior Identification Code)
A 16-bit field containing the Per Hop Behavior
Identification Code of the PHB, or of the set of
PHBs, from which Diffserv resources
are to be reserved. This field MUST be encoded as
specified in Section 2 of [RFC3140].
VDstPort (Virtual Destination Port)
A 16-bit identifier used in the SESSION that
remains constant over the life of the generic
aggregate reservation.
Extended vDstPort (Extended Virtual Destination Port)
An identifier used in the SESSION that remains
constant over the life of the generic aggregate
reservation. The length of this idenitifier is 32-
bits when IPv4 addresses are used and 128 bits when
IPv6 addresses are used.
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A sender(or Aggregator) that wishes to narrow the
scope of a SESSION to the sender-receiver pair (or
Aggregator-Deaggregator pair) SHOULD place its IPv4
or IPv6 address here as a network unique
identifier. A sender (or Aggregator) that wishes to
use a common session with other senders (or
Aggregators) in order to use a shared reservation
across senders (or Aggregators) MUST set this field
to all zeros. In this document, the Extended
vDstPort SHOULD contain the IPv4 or IPv6 address of
the Aggregator.
PCN-domain: a PCN-capable domain; a contiguous set of
PCN-enabled nodes that perform Diffserv scheduling
[RFC2474]; the complete set of PCN-nodes that in
principle can, through PCN-marking packets,
influence decisions about flow admission and
termination for the PCN-domain; includes
the PCN-egress-nodes, which measure these
PCN-marks, and the PCN-ingress-nodes.
PCN-boundary-node: a PCN-node that connects one PCN-domain to a node
either in another PCN-domain or in a non-PCN-domain.
PCN-interior-node: a node in a PCN-domain that is not a PCN-
boundary-node.
PCN-node: a PCN-boundary-node or a PCN-interior-node.
PCN-egress-node: a PCN-boundary-node in its role in handling
traffic as it leaves a PCN-domain. In this
document the PCN-ingress-node operates also as a
deaggregator.
PCN-ingress-node: a PCN-boundary-node in its role in handling
traffic as it enters a PCN-domain. In this
document the PCN-ingress-node operates also as a
Decision Point and aggregator.
PCN-traffic,
PCN-packets,
PCN-BA: a PCN-domain carries traffic of different Diffserv
behavior aggregates (BAs) [RFC2474]. The PCN-BA
uses the PCN mechanisms to carry PCN-traffic, and
the corresponding packets are PCN-packets.
The same network will carry traffic of other
Diffserv BAs. The PCN-BA is
distinguished by a combination of the Diffserv
codepoint (DSCP) and ECN fields.
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Microflow: a single instance of an application-to-application
(from [RFC2474]) flow of packets which is identified by source
address, destination address, protocol id, and
source port, destination port (where applicable).
e2e microflow a microflow where its associated packets are being
forwarded on an E2E path.
PCN-flow: the unit of PCN-traffic that the PCN-boundary-node
admits (or terminates); the unit could be a single
e2e microflow (as defined in [RFC2474]) or some
identifiable collection of microflows.
RSVP generic aggregated reservation: an RSVP reservation that is
identified by using the RSVP SESSION object
for generic RSVP aggregate reservation. This RSVP
SESSION object is based on the RSVP SESSION object
specified in [RFC4860] augmented with the following
information:
o) the IPv4 DestAddress, IPv6 DestAddress SHOULD be
set to the IPv4 or IPv6 destination addresses,
respectively, of the Deaggregator (PCN-egress-
node)
o) PHB-ID (Per Hop Behavior Identification Code)
SHOULD be set equal to PCN-compatible Diffserv
codepoint(s).
o) Extended vDstPort SHOULD be set to the IPv4 or
IPv6 destination addresses, of the Aggregator
(PCN-ingress-node)
Ingress-egress-aggregate (IEA):
The collection of PCN-packets from all PCN-flows
that travel in one direction between a specific pair
of PCN-boundary-nodes. An ingress-egress-aggregate
is identified by the combination of (1) PCN-BA
(i.e., combination of the DSCP and ECN fields),(2)
IP addresses of the specific pair of
PCN-boundary-nodes used by the
ingress-egress-aggregate. In this document one RSVP
generic aggregated reservation is mapped to only
one ingress-egress-aggregate, while one
ingress-egress-aggregate is mapped to either
one or to more than one RSVP generic aggregated
reservations.
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PCN-admission-state:
The state ("admit" or "block") derived by the
Decision Point for a given ingress-egress-aggregate
based on statistics about PCN-packet marking. The
Decision Point decides to admit or block new flows
offered to the aggregate based on the current value
of the PCN-admission-state.
Congestion level estimate (CLE):
The ratio of PCN-marked to total PCN-traffic
(measured in octets) received for a given ingress-
egress-aggregate during a given measurement period.
The CLE is used to derive the PCN-admission-state
and is also used by the report suppression procedure
if report suppression is activated.
t-meas:
A configurable time interval that defines the
measurement period over which the PCN-egress-node
collects statistics relating to PCN-traffic marking.
t-fail:
An interval after which the Decision Point (i.e.,
PCN-ingress-node in this document) concludes that
communication from a given PCN-egress-node has failed
if it has received no reports from the
PCN-egress-node during that interval.
t-recvFail:
A timer per ingress-egress-aggregate that the
Decision point (i.e., PCN-ingress-node) sets every
time it receives an RSVP Aggregated RESV message for
that ingress-egress-aggregate. When its value
reaches t-fail it is assumed that the PCN-ingress-
node has lost contact with the PCN-egress-node.
Therefore the PCN-ingress-node blocks admission of
new PCN-flows into that aggregate and raises a
management alarm.
1.4. Organization of This Document
This document is organized as follows. Section 2 gives an overview of
RSVP extensions and operations. The elements of the used procedures
are specified in Section 3. Section 4 describes the protocol
elements. The security considerations are given in section 5 and the
IANA considerations are provided in Section 6.
2. Overview of RSVP extensions and Operations
2.1 Overview of RSVP Aggregation Procedures in PCN domains
The PCN-boundary-nodes, see Figure 1, can support RSVP SESSIONS for
generic aggregated reservations {RFC4860], which are depending on
ingress-egress-aggregates. In particular, one RSVP generic aggregated
reservation matches to only one ingress-egress-aggregate.
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However, one ingress-egress-aggregate matches to either
one or more than one RSVP generic aggregated reservations.
In addition, to comply with this specification it is considered that
the PCN-boundary nodes are able to distinguish by using the addresses
that the RSVP messages are addressed to, and process (1) RSVP
SESSIONS for generic aggregated sessions and their messages according
to [RFC4860], (2) e2e RSVP sessions and messages according to
[RFC2205]. Furthermore, it is considered that by configuration the
PCN-interior-nodes are not able to distinguish neither RSVP generic
aggregated sessions and their associated messages [RFC4860], nor e2e
RSVP sessions and their associated messages [RFC2205].
--------------------------
/ PCN-domain \
|----| | | |----|
H--| R |\ |-----| |------| /| R |-->H
H--| |\\| | |---| |---| | |//| |-->H
|----| \| | | I | | I | | |/ |----|
| Agg |======================>| Deag |
/| | | | | | | |\
H--------//| | |---| |---| | |\\-------->H
H--------/ |-----| |------| \-------->H
| |
\ /
--------------------------
H = Host requesting end-to-end RSVP reservations
R = RSVP router
Agg = Aggregator (PCN-ingress-node)
Deag = Deaggregator (PCN-egress-node)
I = Interior Router (PCN-interior-node)
--> = E2E RSVP reservation
==> = Aggregate RSVP reservation
Figure 1 : Aggregation of E2E Reservations
over Generic Aggregate RSVP Reservations
in PCN domains, based on [RFC4860]
Moreover, each Aggregator and Deaggregator (i.e., PCN-boundary-nodes)
MUST support policies to initiate and maintain for each pair of
PCN-boundary-nodes of the same PCN-domain one ingress-egress-
aggregate. Both the Aggregator and Deaggregator can maintain one or
more RSVP generic aggregated Reservations, but the Deaggregator is
the entity that initiates these RSVP generic aggregated reservations.
Note that one RSVP generic aggregated reservation matches to only
one ingress-egress-aggregate, while one ingress-egress-aggregate
matches to either one or to more than one RSVP generic aggregated
reservations. This can be accomplished by using for the different
RSVP generic aggregated reservations the same combinations of
ingress and egress identifiers, but with a different PHB-ID value
(see [RFC4860]). The procedures for aggregation of E2E reservations
over generic aggregate RSVP reservations are the same as the
procedures specified in Section 4 of [RFC4860], augmented with the
following ones, see also Section 2.5:
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o) Aggregator (PCN-ingress-node) and Deaggregator (PCN-egress-node)
MUST be able to determine, for each received e2e Path message, in
which ingress-egress-aggregate it can be mapped to.
o) Depending on policies the Aggregator and Deaggregator MUST be able
to decide whether a RSVP generic aggregate reservations can be
mapped into an ingress-egress-aggregate, see Section 2.5 for more
details.
2.2 PCN Marking and encoding and transport of pre-congestion
information
The method of PCN marking within the PCN domain is based on
[RFC5670]. In addition, the method of encoding and transport of pre-
congestion information is based [RFC6660]. The PHB-ID (Per Hop
Behavior Identification Code) used SHOULD be set equal
to PCN-compatible Diffserv codepoint(s).
2.3. Traffic Classification Within The Aggregation Region
The PCN-ingress marks a PCN-BA using PCN-marking (i.e., combination
of the DSCP and ECN fields), which interior nodes use to
classify PCN-traffic. The PCN-traffic (e.g., e2e microflows)
belonging to an ingress-egress-aggregate can be classified only at
the PCN-boundary-nodes using the combination of (1) PCN-BA (i.e.,
combination of the DSCP and ECN fields), (2) IP addresses of the
specific pair of PCN-boundary-nodes used by a ingress-egress-
aggregate. The method of classification and traffic conditioning of
PCN-traffic and non-PCN traffic and PHB configuration is described in
[RFC6661] and [RFC6662]. Moreover, the PCN-traffic (e.g., e2e
microflows) belonging to a RSVP generic aggregated reservation can be
classified only at the PCN-boundary-nodes (i.e., Aggregator and
Deaggregator) by using the RSVP SESSION object for RSVP generic
aggregated reservations, see Section 2.1 of [RFC4860]. It is
considered that tunnels need to be used between Aggregators and
Deaggregators, using the same procedures as specified in Section 4 of
[RFC4860].
2.4. Deaggregator (PCN-egress-node) Determination
To comply with this specification it is considered that in order to
determine the Deaggregator, the same methods can be used as the ones
described in Section 4 of [RFC4860] and in Section 1.4.2 of
[RFC3175]. In the context of this document this can be determined
very easily, since from the point of RSVP, the next RSVP hop for the
Aggregator in the downstream direction is the Deaggregator and the
next RSVP hop for the Deaggregator in the upstream direction is the
Aggregator.
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2.5. Mapping E2E Reservations Onto Aggregate Reservations
To comply with this specification it is considered that for the
mapping of e2e reservations onto aggregate reservations, the same
methods can be used as the ones described in Section 4 of [RFC4860],
augmented by the following rules:
o) An Aggregator (PCN-ingress-node) MUST be able to determine for
each e2e Path message that arrives at its external interface in
which ingress-egress-aggregate it can be mapped to. This is
possible, see also Section 2.4, since from the point of RSVP, the
Deaggregator (PCN-egress-node) is one RSVP hop away from the
Aggregator (PCN-ingress-node). The Aggregator (PCN-ingress-node)
uses PCN related information sent by the Deaggregator to
map RSVP generic aggregated states to ingress-egress-aggregates.
o) A PCN-ingress-node (Aggregator) or PCN-egress-node (Deaggregator)
MUST use one or more policies to determine whether a RSVP generic
aggregated reservation can be mapped into an ingress-egress-
aggregate. Note that one RSVP generic aggregated reservation
matches to only one ingress-egress-aggregate, while one ingress-
egress-aggregate matches to either one or to more than one RSVP
generic aggregated reservations. The Aggregator or the
Deaggregator MUST be able to map RSVP generic aggregated
reservations into ingress-egress-aggregates. This can be
accomplished by using for the different RSVP generic aggregated
reservations the same combinations of ingress and egress
identifiers, but with a different PHB-ID value (see [RFC4860]). In
particular, each RSVP generic aggregated reservation is identified
by using the RSVP SESSION object [RFC4860]. The RSVP SESSION
object for generic aggregate reservations is based on the RSVP
SESSION object specified in [RFC4860] augmented with the following
information:
o) the IPv4 DestAddress, IPv6 DestAddress MUST be set to the IPv4
or IPv6 destination addresses, respectively, of the
Deaggregator (PCN-egress-node), see [RFC4860]. Note that the
PCN-domain is considered as being only one RSVP hop (for
Generic aggregated RSVP or e2e RSVP). This means that the next
RSVP hop for the Aggregator in the downstream direction is the
Deaggregator and the next RSVP hop for the Deaggregator in the
upstream direction is the Aggregator.
o) PHB-ID (Per Hop Behavior Identification Code) SHOULD be set
equal to PCN-compatible Diffserv codepoint(s).
o) Extended vDstPort SHOULD be set to the IPv4 or IPv6 destination
addresses, of the Aggregator (PCN-ingress-node), see [RFC4860].
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2.6. Size of Aggregate Reservations
To comply with this specification it is considered that for the
determination of the size of the RSVP generic aggregate reservations,
the same methods can be used as the ones described in [RFC4860] and
Section 1.4.4. of [RFC3175].
2.7. E2E Path ADSPEC update
To comply with this specification it is considered that for the
update of the e2e Path ADSPEC, the same methods can be used as the
ones described in [RFC4860].
2.8. Intra-domain Routes
The PCN-interior-nodes are neither maintaining e2e RSVP nor RSVP
generic aggregation states and reservations. Therefore, intra-domain
route changes will not affect intra-domain reservations since such
reservations are not maintained by the PCN-interior-nodes.
Furthermore, it is considered that by configuration, the PCN-
interior-nodes are not able to distinguish neither RSVP generic
aggregated sessions and their associated messages [RFC4860], nor e2e
RSVP sessions and their associated messages [RFC2205].
2.9. Inter-domain Routes
The PCN-charter scope precludes inter-domain considerations. However,
for solving inter-domain routes changes associated with the operation
of the RSVP messages, the same methods SHOULD be used as the ones
described in [RFC4860] and in Section 1.4.7 of
[RFC3175].
2.10. Reservations for Multicast Sessions
PCN does not consider reservations for multicast sessions.
2.11. Multi-level Aggregation
PCN does not consider multi-level aggregations within the PCN domain.
Therefore, the PCN-interior-nodes are not supporting multi-level
aggregation procedures. However, the Aggregator and Deaggregator
SHOULD support the multi-level aggregation procedures specified in
[RFC4860] and in Section 1.4.9 of [RFC3175].
2.12. Reliability Issues
To comply with this specification it is considered that for solving
possible reliability issues, the same methods can be used as the ones
described in Section 4 of [RFC4860].
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2.13. Message Integrity and Node Authentication
To comply with this specification it is considered that for message
integrity and node authentication, the same methods can be used as
the ones described in Section 4 of [RFC4860] and [RFC5559].
3. Elements of Procedure
This section describes the procedures used to implement the
aggregated RSVP procedure over PCN. It is considered that the
procedures for aggregation of e2e reservations over generic aggregate
RSVP reservations are same as the procedures specified in Section
4 of [RFC4860]. Please refer to [RFC4860] for all the below error
cases:
*) Incomplete message
*) Unexpected objects
3.1. Receipt of E2E Path Message By PCN-ingress-node (aggregating
router)
When the e2e Path message arrives at the exterior interface of the
Aggregator, i.e., PCN-ingress-node, then standard RSVP generic
aggregation [RFC4860] procedures are used, augmented with the
following rules:
o) The e2e RSVP reservation session associated with an e2e Path
message that arrives at the external interface of the PCN-
ingress-node is mapped/matched onto an PCN ingress-egress-
aggregate.
o) If the timer t-recvFail does NOT expire for a given PCN-egress-
node, then:
o) If (1) the PCN-admission state for the ingress-egress-
aggregate associated with the received e2e Path is "admit",
the Decision Point (i.e., PCN-ingress-node) SHOULD allow the
new flow to be admitted to that PCN ingress-egress-
aggregate, see [RFC6661] and [RFC6662]. The e2e Path message
is then forwarded towards destination.
o) If for the same PCN ingress-egress-aggregate
the PCN-admission-state is "block", the request SHOULD NOT
be admitted by the PCN-ingress-node (Aggregator) and an e2e
PathErr message SHOULD be generated, using standard e2e RSVP
procedures [RFC4495]. This e2e PathErr message is sent to
the originating sender of the e2e Path message, using
standard e2e RSVP procedures [RFC2205], [RFC4495]. This e2e
PathErr message is sent to the originating sender of the e2e
Path message. The e2e RSVP error code "01: Admission Control
failure" and the "Sub-code = 2: Requested bandwidth
unavailable " specified in Appendix B of [RFC2205] SHOULD be
used for this purpose.
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When the originating sender receives this e2e PathErr
message it SHOULD apply a PCN specific policy to generate an
e2e PathTear message to release all the possible Path states
initiated on the e2e RSVP aware nodes on the path towards
the PCN-ingress-node (Aggregator).
o) If the timer t-recvFail expires for a given PCN-egress-node, the
Decision Point (i.e., PCN-ingress-node) SHOULD NOT
allow the e2e microflow (i.e., PCN-flow) to be admitted to that
PCN ingress-egress-aggregate, see [RFC6661], [RFC6662]. The
admission or rejection procedure of a PCN-flow into the PCN-
domain is defined in detail in: [RFC6661] and [RFC6662].
If the Aggregator is not able to admit the e2e microflow it
SHOULD then generate an e2e PathErr message using standard e2e
RSVP procedures [RFC4495]. This e2e PathErr message is sent to
the originating sender of the e2e Path message. The e2e RSVP
error code "01: Admission Control failure" and the "Sub-code =
2: Requested bandwidth unavailable " specified in Appendix B of
[RFC2205] SHOULD be used for this purpose. When the originating
sender receives this e2e PathErr message it SHOULD apply a PCN
specific policy to generate an e2e PathTear message to release all
the possible Path states initiated on the e2e RSVP aware nodes on
the path towards the PCN-ingress-node (Aggregator).
The way of how the PCN-admission-state is maintained is specified in
[RFC6661] and [RFC6662]. The way of how the RSVP generic aggregated
reservation state is maintained is specified in [RFC4860].
3.2. Handling Of E2E Path Message By Interior Routers
The e2e Path messages traverse zero or more PCN-interior-nodes.
The PCN-interior-nodes receive the e2e Path message on an interior
interface and forward it on another interior interface. It is
considered that by configuration the PCN-interior-nodes are not able
to distinguish neither e2e RSVP sessions and their associated
messages [RFC2205]. Therefore, the e2e Path messages are simply
forwarded as normal IP datagrams.
3.3. Receipt of E2E Path Message By PCN-egress-node (Deaggregating
router)
When receiving the e2e Path message the PCN-egress-node
(Deaggregator) performs main regular [RFC4860] procedures, augmented
with the following rules:
o) The PCN-egress-node MUST NOT perform the RSVP-TTL vs IP TTL-
check and MUST NOT update the ADspec Break bit. This is because
the whole PCN-domain is effectively handled by e2e RSVP as a
virtual link on which integrated service is indeed supported
(and admission control performed) so that the Break bit MUST
NOT be set, see also [draft-lefaucheur-rsvp-ecn-01].
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o) If the Deaggregator does not maintain any RSVP generic
aggregated reservation states, then one or more of such states
are created during this step. Moreover, also at this step
the Deaggregator maps the new generated RSVP generic
aggregated reservations onto one ingress-egress-aggregate
maintained by the Deaggregator (PCN-egress-node), see Section
2.5.
The PCN-egress-nodes forwards the e2e Path message towards the
receiver.
3.4. Initiation of new Aggregate Path Message By PCN-ingress-node
(Aggregating Router)
To comply with this specification it is considered that for the
initiation of the new RSVP aggregated Path message by the PCN-
ingress-node (Aggregator), the same methods can be used as the ones
described in [RFC4860].
3.5. Handling Of new Aggregate Path Message By Interior Routers
The Aggregate Path messages traverse zero or more PCN-interior-nodes.
The PCN-interior-nodes receive the e2e Path message on an interior
interface and forward it on another interior interface.
It is considered that by configuration, the PCN-interior-nodes are
not able to distinguish neither RSVP generic aggregated sessions and
their associated messages [RFC4860]. Therefore, the Aggregated Path
messages are simply forwarded as normal IP datagrams.
3.6. Handling of E2E Resv Message by Deaggregating Router
When the e2e Resv message arrives at the exterior interface of the
Deaggregator, i.e., PCN-egress-node, then standard RSVP
aggregation [RFC4860] procedures are used. It is important to be
noticed that according to [RFC4860] the Deaggregator is responsible
of performing admission control of the E2E RESV onto the generic
aggregate reservation.
3.7. Handling Of E2E Resv Message By Interior Routers
The e2e Resv messages traverse zero or more PCN-interior-nodes. The
PCN-interior-nodes receive the e2e Resv message on an interior
interface and forward it on another interior interface. It is
considered that by configuration the PCN-interior-nodes are not able
to distinguish neither e2e RSVP sessions and their associated
messages [RFC2205]. Therefore, the e2e Resv messages are simply
forwarded as normal IP datagrams.
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3.8. Initiation of New Aggregate Resv Message By Deaggregating Router
To comply with this specification it is considered that for the
initiation of the new RSVP aggregated Resv message by the PCN-
egress-node (Deaggregator), the same methods can be used as the ones
described in Section 4 of [RFC4860] augmented with the following
rules:
o) At the end of each t-meas measurement interval, or less
frequently if "optional report suppression" is activated, see
[RFC6661], and [RFC6662], the PCN-egress-node MUST include the
new PCN object that will be sent to the associated Decision
Point (i.e., PCN-ingress-node). The PCN-egress-node reports the
data it measures for a particular ingress-egress-aggregate in a
PCN object, as specified in Section 4 of this document (see
[RFC6661], and [RFC6662]). The address of the PCN-ingress-
node, i.e., Aggregator, is the one specified in the same
ingress-egress-aggregate. It is considered that the ingress-
egress-aggregate state stores both IP addresses of the PCN-
ingress-node, i.e., Aggregator, and of the IP-egress-node, i.e.,
Deaggregator.
3.9. Handling of Aggregate Resv Message by Interior Routers
The Aggregated Resv messages traverse zero or more PCN-interior-
nodes. The PCN-interior-nodes receive the Aggregated Resv message on
an interior interface and forward it on another interior interface.
It is considered that by configuration, the PCN-interior-nodes are
not able to distinguish neither RSVP generic aggregated sessions and
their associated messages [RFC4860]. Therefore, the Aggregated Resv
messages are simply forwarded as normal IP datagrams.
3.10. Handling of E2E Resv Message by Aggregating Router
When the e2e Resv message arrives at the interior interface of the
Aggregating router, i.e., PCN-ingress-node, then standard RSVP
aggregation [RFC4860] procedures are used.
3.11. Handling of Aggregated Resv Message by Aggregating Router
When the Aggregated Resv message arrives at the interior interface of
the Aggregating router, i.e., PCN-ingress-node, then standard RSVP
aggregation [RFC4860] procedures are used, augmented with the
following rules:
o) If the Decision Point is not collocated with the PCN-ingress-
node, then other procedures need to be specified of handling the
Aggregated Resv Message by the Aggregating router, i.e., PCN-
ingress-node. Even though these procedures are out of the scope
of this document, the PCN-ingress-node can refer to a central
decision point which can respond to the PCN ingress as per
[RFC2753]
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o) If the Decision point is collocated with the PCN-ingress-node,
then the PCN-ingress-node (i.e. Aggregator) SHOULD use the
information carried by the PCN objects, see Section 4, to map
the RSVP generic aggregated state onto the maintained ingress-
egress-aggregate state at the Aggregator (PCN-ingress-node).
Furthermore, the Aggregator follows the steps specified in
[RFC6661], [RFC6662]. Using the information contained in the PCN
object the Aggregator (i.e., PCN-ingress-node) can decide
whether the PCN-admission state for the ingress-egress-aggregate
is "admit" or "reject". Moreover, when the Aggregator (i.e.,
PCN-ingress-node) needs to terminate an amount of traffic
associated with one ingress-egress-aggregate (see bullet 2 in
Section 3.3.2 of [RFC6661] and [RFC6662]), then several
procedures of terminating e2e microflows can be deployed. The
default procedure of terminating e2e microflows (i.e., PCN-
flows) is as follows, see e.g., [RFC6661].
For the same ingress-egress-aggregate, select a number of e2e
microflows to be terminated in order to decrease the total
incoming amount of bandwidth associated with one ingress-egress-
aggregate by the amount of traffic to be terminated, see above.
In this situation the same mechanisms for terminating an e2e
microflow can be followed as specified in [RFC2205]. However,
based on a local policy, the Aggregator could use other ways of
selecting which microflows should be terminated.
For example, for the same ingress-egress-aggregate, select a
number of e2e microflows to be terminated or to reduce their
reserved bandwidth in order to decrease the total incoming
amount of bandwidth associated with one ingress-egress-aggregate
by the amount of traffic to be terminated. In this situation the
same mechanisms for terminating an e2e microflow or reducing
bandwidth associated with an e2e microflow can be followed as
specified in [RFC4495].
3.12. Removal of E2E Reservation
To comply with this specification it is considered that for the
removal of e2e reservations, the same methods can be used as the ones
described in Section 4 of [RFC4860] and [RFC4495], augmented by the
methods described in Section 3.11.
3.13. Removal of Aggregate Reservation
To comply with this specification it is considered that for the
removal of RSVP generic aggregated reservations, the same methods can
be used as the ones described in Section 4 of [RFC4860] and Section
2.10 of [RFC3175]. In particular, should an aggregate reservation go
away (presumably due to a configuration change, route change, or
policy event), the e2e reservations it supports are no longer active.
They must be treated accordingly.
3.14. Handling of Data On Reserved E2E Flow by Aggregating Router
The handling of data on the reserved e2e Flow by Aggregating Router
is using the procedures described in [RFC4860] augmented with:
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o) Regarding, PCN marking and traffic classification the procedures
defined in Section 2.2 and 2.4 of this document are used.
3.15. Procedures for Multicast Sessions
In this document no multicast sessions are considered.
3.16. Misconfiguration of PCN-node
In an event where a PCN-node is misconfigured within a PCN-domain,
the desired behavior is same as described in Section 3.9. Therefore,
the Aggregated Resv messages are simply forwarded as normal IP
datagrams.
4. Protocol Elements
The protocol elements in this document are using the protocol
elements defined in Section 4 [RFC4860] and Section 3 of [RFC3175]
augmented with the following rules:
o) A PCN-egress-node (i.e., Deaggregator) SHOULD send periodically
and at the end of each t-meas measurement interval, or less
frequently if "optional report suppression" is activated, an
(refresh) aggregated RSVP message to the PCN-ingress-node (i.e.
aggregator), see [RFC6661] and [RFC6662].
o) the DSCP value included in the SESSION object, SHOULD be set equal
to a PCN-compatible Diffserv codepoint.
o) An aggregated Resv message MUST carry one or more PCN
objects, see Section 4.1, to report the data measured by an
PCN-egress-node (i.e., Deaggregator).
o) As described in [RFC6661], [RFC6663], PCN reports
from the PCN-egress-node (Deaggregator) to the decision point may
contain flow identifiers for individual flows within an
ingress-egress-aggregate that have recently experienced
excess-marking. Hence, the PCN report messages used by the PCN CL
edge behavior MUST be capable of carrying sequences of octet
strings constituting such identifiers. When the PCN CL edge
behavior is used, the individual flow identifiers need to be
included in specific PCN objects, see Section 4.1
(RSVP-AGGREGATE-IPv4-PCN-CL-FLIDs,
RSVP-AGGREGATE-IPv6-PCN-CL-FLIDs)
4.1 PCN objects
The PCN object reports data measured by a PCN-egress-node and
carried by the generic aggregated RESV messages specified in
[RFC4860]. PCN objects are defined for different PCN edge behavior
drafts. This document defines six types of PCN objects that belong
into the SESSION Class and need to be carried by
Aggregate RESV messages. These objects are:
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RSVP-AGGREGATE-IPv4-PCN-SM, RSVP-AGGREGATE-IPv6-PCN-SM,
RSVP-AGGREGATE-IPv4-PCN-CL, RSVP-AGGREGATE-IPv6-PCN-CL,
RSVP-AGGREGATE-IPv4-PCN-CL-FLIDs, RSVP-AGGREGATE-IPv6-PCN-CL-FLIDs.
o) RSVP-AGGREGATE-IPv4-PCN-SM: Single Marking (SM) PCN object, when
IPv4 addresses are used:
Class = 1 (SESSION)
C-Type = RSVP-AGGREGATE-IPv4-PCN-SM (to be replaced by IANA)
+-------------+-------------+-------------+-------------+
| IPv4 PCN-ingress-node Address (4 bytes) |
+-------------+-------------+-------------+-------------+
| IPv4 PCN-egress-node Address (4 bytes) |
+-------------+-------------+-------------+-------------+
| rate of not marked PCN-traffic (NM-rate) |
+-------------+-------------+-------------+-------------+
| rate of PCN-marked PCN-traffic (PM-rate) |
+-------------+-------------+-------------+-------------|
o) RSVP-AGGREGATE-IPv6-PCN-SM: Single Marking (SM) PCN object, when
IPv6 addresses are used:
Class = 1 (SESSION)
C-Type = RSVP-AGGREGATE-IPv6-PCN-SM (to be replaced by IANA)
+-------------+-------------+-------------+-------------+
| |
+ +
| |
+ IPv6 PCN-ingress-node Address (16 bytes) +
| |
+ +
| |
+-------------+-------------+-------------+-------------+
| |
+ +
| |
+ IPv6 PCN-egress-node Address (16 bytes) +
| |
+ +
| |
+-------------+-------------+-------------+-------------+
| rate of not marked PCN-traffic (NM-rate) |
+-------------+-------------+-------------+-------------+
| rate of PCN-marked PCN-traffic (PM-rate) |
+-------------+-------------+-------------+-------------+
o) RSVP-AGGREGATE-IPv4-PCN-CL: Controlled (CL) PCN object, IPv4
addresses are used:
Class = 1 (SESSION)
C-Type = RSVP-AGGREGATE-IPv4-PCN-CL (To be replaced by IANA)
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+-------------+-------------+-------------+-------------+
| IPv4 PCN-ingress-node Address (4 bytes) |
+-------------+-------------+-------------+-------------+
| IPv4 PCN-egress-node Address (4 bytes) |
+-------------+-------------+-------------+-------------+
| rate of not marked PCN-traffic (NM-rate) |
+-------------+-------------+-------------+-------------+
| rate of threshold-marked PCN-traffic (ThM-rate) |
+-------------+-------------+-------------+-------------+
| rate of excess-traffic-marked PCN-traffic (ETM-rate) |
+-------------+-------------+-------------+-------------+
o) RSVP-AGGREGATE-IPv6-PCN-CL: Controlled (CL) PCN object, IPv6
addresses are used:
Class = 1 (SESSION)
C-Type = RSVP-AGGREGATE-IPv6-PCN-CL (to be replaced by IANA)
+-------------+-------------+-------------+-------------+
| |
+ +
| |
+ IPv6 PCN-ingress-node Address (16 bytes) +
| |
+ +
| |
+-------------+-------------+-------------+-------------+
| |
+ +
| |
+ IPv6 PCN-egress-node Address (16 bytes) +
| |
+ +
| |
+-------------+-------------+-------------+-------------+
| rate of not marked PCN-traffic (NM-rate) |
+-------------+-------------+-------------+-------------+
| rate of threshold-marked PCN-traffic (ThM-rate) |
+-------------+-------------+-------------+-------------+
| rate of excess-traffic-marked PCN-traffic (ETM-rate) |
+-------------+-------------+-------------+-------------+
The fields carried by the PCN object are specified in
[RFC6663], [RFC6661] and [RFC6662]:
o the IPv4 or IPv6 address of the PCN-ingress-node and the IPv4
or IPv6 address of the PCN-egress-node; together they specify the
ingress-egress-aggregate to which the report refers. According to
[RFC6663] the report should carry the identifier of the PCN-
ingress-node and the identifier of the PCN-egress-node (typically
their IP addresses);
o rate of not-marked PCN-traffic (NM-rate) in octets/second; its
format is a 32-bit IEEE floating point number;
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o rate of PCN-marked traffic (PM-rate) in octets/second; its format
is a 32-bit IEEE floating point number;
o rate of threshold-marked PCN traffic (ThM-rate) in
octets/second; its format is a 32-bit IEEE floating point number;
o rate of excess-traffic-marked traffic (ETM-rate) in
octets/second; its format is a 32-bit IEEE floating point number;
o) RSVP-AGGREGATE-IPv4-PCN-CL-FLIDs: Controlled (CL) PCN CL Flow IDs
object, IPv4 addresses are used:
Class = 1 (SESSION)
C-Type = RSVP-AGGREGATE-IPv4-PCN-CL-FLIDs (to be replaced by IANA)
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+
| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// //
+ +
| Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o) Length (1 byte): the length of the
RSVP-AGGREGATE-IPv4-PCN-CL-FLIDs object in units of 16 bytes.
This field is used to specify the number of IPv4 flow IDs
carried by this object. Each flow ID is represented by the
combination of each subsequent 5 tuple:
Source address, Destination address, Source Port,
Destination Port and Protocol number.
If Length is 0 then the RSVP-AGGREGATE-IPv4-PCN-CL-FLIDs is
empty.
o) Source address (4 bytes): The IPv4 source address.
o) Destination address (4 bytes): The IPv4 destination address.
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o) Protocol (1 byte): The IP protocol number. It refers to the
true upper layer protocol carried by the packets.
o) Source Port (2 bytes): contains the source port number.
o) Destination Port (2 bytes): contains the destination port
number.
o) RSVP-AGGREGATE-IPv6-PCN-CL-FLIDs: Controlled (CL) PCN CL Flow IDs
object, IPv6 addresses are used:
Class = 1 (SESSION)
C-Type = RSVP-AGGREGATE-IPv6-PCN-CL-FLIDs (To be replaced by IANA)
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+
| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Source Address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Destination Address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// //
+ +
| |
| Source Address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Destination Address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o) Length (1 byte): the length of the
RSVP-AGGREGATE-IPv6-PCN-CL-FLIDs object in units of 40 bytes.
This field is used to specify the number of flow IDs carried by
this object. Each flow ID is represented by the combination of
each subsequent 5 tuple fields:
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Source address, Destination address, Source Port,
Destination Port and Protocol number.
If Length is 0 then the RSVP-AGGREGATE-IPv6-PCN-CL-FLIDs object
is empty.
o) Source address (16 bytes): The IPv6 source address.
o) Destination address (16 bytes): The IPv6 destination address.
o) Protocol (1 byte): The IP protocol number. It refers to the
true upper layer protocol carried by the packets.
o) Source Port (2 bytes): contains the source port number.
o) Destination Port (2 bytes): contains the destination port
number.
5. Security Considerations
The same security considerations specified in [RFC2205], [RFC4230],
[RFC4860], [RFC5559] and [RFC6411].
6. IANA Considerations
This document makes the following requests to the IANA.
IANA needs to modify the RSVP parameters registry, 'Class Names,
Class Numbers, and Class Types' subregistry, and assigned 6 new C-
Types under the existing SESSION Class (Class number 1), as described
Below, see Section 4.1:
Class
Number Class Name Reference
------ ----------------------- ---------
1 SESSION [RFC2205]
Class Types or C-Types:
19? RSVP-AGGREGATE-IPv4-PCN-SM this document
20? RSVP-AGGREGATE-IPv6-PCN-SM this document
21? RSVP-AGGREGATE-IPv4-PCN-CL this document
22? RSVP-AGGREGATE-IPv6-PCN-CL this document
23? RSVP-AGGREGATE-IPv4-PCN-CL-FLIDs this document
24? RSVP-AGGREGATE-IPv6-PCN-CL-FLIDs this document
7. Acknowledgments
We would like to thank the authors of [draft-lefaucheur-rsvp-ecn-
01.txt], since some ideas used in this document are based on the work
initiated in [draft-lefaucheur-rsvp-ecn-01.txt]. Moreover, we would
like to thank Bob Briscoe, David Black, Ken Carlberg, Tom Taylor,
Philip Eardley, Michael Menth, Toby Moncaster, Francois Le Faucheur,
James Polk and Lixia Zhang for the provided comments.
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8. Normative References
[RFC6661] T. Taylor, A, Charny, F. Huang,
G. Karagiannis, M. Menth, "PCN Boundary Node Behaviour for the
Controlled Load (CL) Mode of Operation", July
2012.
[RFC6662] A. Charny, J. Zhang,
G. Karagiannis, M. Menth, T. Taylor, "PCN Boundary Node Behaviour
for the Single Marking (SM) Mode of Operation",
July 2012.
[RFC6663] G. Karagiannis, T. Taylor,
K. Chan, M. Menth, P. Eardley, " Requirements for Signaling of (Pre-)
Congestion Information in a DiffServ Domain",
July 2012.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2205] Braden, R., ed., et al., "Resource ReSerVation Protocol
(RSVP)- Functional Specification", RFC 2205, September 1997.
[RFC3140] Black, D., Brim, S., Carpenter, B., and F. Le
Faucheur, "Per Hop Behavior Identification Codes",
RFC 3140, June 2001.
[RFC3175] Baker, F., Iturralde, C., Le Faucheur, F., and B. Davie,
"Aggregation of RSVP for IPv4 and IPv6 Reservations", RFC 3175,
September 2001.
[RFC4495] Polk, J. and S. Dhesikan, "A Resource Reservation
Protocol (RSVP) Extension for the Reduction of
Bandwidth of a Reservation Flow", RFC 4495, May 2006.
[RFC4860] F. Le Faucheur, B. Davie, P. Bose, C. Christou, M.
Davenport, "Generic Aggregate Resource ReSerVation Protocol (RSVP)
Reservations", RFC4860, May 2007.
[RFC5670] Eardley, P., "Metering and Marking Behaviour of PCN-Nodes",
RFC 5670, November 2009.
[RFC6660] Moncaster, T., Briscoe, B., and M. Menth, "Baseline
Encoding and Transport of Pre-Congestion Information", RFC 6660,
July 2012.
9. Informative References
[draft-lefaucheur-rsvp-ecn-01.txt] Le Faucheur, F., Charny, A.,
Briscoe, B., Eardley, P., Chan, K., and J. Babiarz, "RSVP Extensions
for Admission Control over Diffserv using Pre-congestion
Notification (PCN) (Work in progress)", June 2006.
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Internet-Draft Aggregated RSVP over PCN October 2013
[RFC1633] Braden, R., Clark, D., and S. Shenker, "Integrated
Services in the Internet Architecture: an Overview", RFC 1633, June
1994.
[RFC2211] J. Wroclawski, Specification of the Controlled-Load Network
Element Service, September 1997
[RFC2212] S. Shenker et al., Specification of Guaranteed Quality of
Service, September 1997
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS Field) in the
IPv4 and IPv6 Headers", RFC 2474, December 1998.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z. and
W. Weiss, "A framework for Differentiated Services", RFC 2475,
December 1998.
[RFC2998] Bernet, Y., Yavatkar, R., Ford, P., Baker, F., Zhang, L.,
Speer, M., Braden, R., Davie, B., Wroclawski, J. and E. Felstaine, "A
Framework for Integrated Services Operation Over DiffServ Networks",
RFC 2998, November 2000.
[RFC4230] H. Tschofenig, R. Graveman, "RSVP Security Properties",
RFC 4230, December 2005.
[RFC5559] Eardley, P., "Pre-Congestion Notification (PCN)
Architecture", RFC 5559, June 2009.
[RFC6411] M. Behringer, F. Le Faucheur, B. Weis, "Applicability of
Keying Methods for RSVP Security", RFC 6411, October 2011.
[SIG-NESTED] Baker, F. and P. Bose, "QoS Signaling in a Nested
Virtual Private Network", Work in Progress, July 2007.
[RFC2753] Yavatkar, R., D. Pendarakis and R. Guerin, "A Framework for
Policy-based Admission Control", January 2000.
10. Appendix A: Example Signaling Flow
This appendix is based on the appendix provided in [RFC4860]. In
particular, it provides an example signaling flow of the
specification detailed in Section 3 and 4. This signaling flow
assumes an environment where E2E reservations are aggregated over
generic aggregate RSVP reservations and applied over a PCN domain. In
particular the Aggregator (PCN-ingress-node) and Deaggregator (PCN-
egress-node) are located at the boundaries of the PCN domain. The
PCN-interior-nodes are located within the PCN-domain, between the
PCN-boundary nodes, but are not shown in this Figure. It illustrates
a possible RSVP message flow that could take place in the successful
establishment of a unicast E2E reservation that is the first between
a given pair of Aggregator/Deaggregator.
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Aggregator (PCN-ingress-node) Deaggregator (PCN-egress-node)
E2E Path
----------->
(1)
E2E Path
------------------------------->
(2)
E2E PathErr(New-agg-needed,SOI=GAx)
<----------------------------------
E2E PathErr(New-agg-needed,SOI=GAy)
<----------------------------------
(3)
AggPath(Session=GAx)
------------------------------->
AggPath(Session=GAy)
------------------------------->
(4)
E2E Path
----------->
(5)
AggResv (Session=GAx) (PCN object)
<-------------------------------
AggResv (Session=GAy) (PCN object)
<-------------------------------
(6)
AggResvConfirm (Session=GAx)
------------------------------>
AggResvConfirm (Session=GAy)
------------------------------>
(7)
E2E Resv
<---------
(8)
E2E Resv (SOI=GAx)
<-----------------------------
(9)
E2E Resv
<-----------
(1) The Aggregator (PCN-ingress-node) maps the e2e RSVP reservation
session associated with the e2e Path message onto an PCN ingress-
egress-aggregate. The Aggregator forwards e2e Path into the
aggregation region after modifying its IP protocol number to
RSVP-E2E-IGNORE. Note that in this case it is considered that the
PCN-admission-state is "admit", see Section 3.1. Otherwise, the
e2e Path will not be forwarded into the aggregation region and
the steps associated with the PCN-admission-state is "block"
situation specified in Section 3.1 will be followed.
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(2) Let's assume no Aggregate Path exists. To be able to accurately
update the ADSPEC of the e2e Path, the Deaggregator needs the
ADSPEC of Aggregate Path. In this example, the Deaggregator
elects to instruct the Aggregator to set up Aggregate Path states
for the two supported PHB-IDs. To do that, the Deaggregator
sends two e2e PathErr messages with a New-Agg-Needed PathErr
code. Both PathErr messages also contain a SESSION-OF-INTEREST
(SOI) object. In the first e2e PathErr, the SOI contains a
GENERIC-AGGREGATE SESSION (GAx) whose PHB-ID is set to x. In the
second e2e PathErr, the SOI contains a GENERIC-AGGREGATE SESSION
(GAy) whose PHB-ID is set to y. In both messages the GENERIC-
AGGREGATE SESSION contains an interface-independent Deaggregator
address inside the DestAddress and appropriate values inside the
vDstPort and Extended vDstPort fields.
(3) The Aggregator follows the request from the Deaggregator and
signals an Aggregate Path for both GENERIC-AGGREGATE Sessions
(GAx and GAy).
(4) The Deaggregator takes into account the information contained in
the ADSPEC from both Aggregate Paths and updates the e2e Path
ADSPEC accordingly. The Deaggregator also modifies the e2e Path
IP protocol number to RSVP before forwarding it.
(5) In this example, the Deaggregator elects to immediately proceed
with establishment of generic aggregate reservations for both
PHB-IDs. In effect, the Deaggregator can be seen as anticipating
the actual demand of e2e reservations so that resources are
available on the generic aggregate reservations when the e2e Resv
requests arrive, in order to speed up establishment of e2e
reservations.
At this step the Deaggregator maps the new generated RSVP generic
aggregated reservations onto one ingress-egress-aggregate
maintained by the Deaggregator (PCN-egress-node), see Section
3.3. Moreover, the Deaggregator, depending on the used
PCN edge behaviour and IP version, it includes one of the
following PCN objects specified in Section 4.1:
RSVP-AGGREGATE-IPv4-PCN-SM, RSVP-AGGREGATE-IPv6-PCN-SM,
RSVP-AGGREGATE-IPv4-PCN-CL or RSVP-AGGREGATE-IPv6-PCN-CL.
Here it is also Assumed that the Deaggregator includes the
optional Resv Confirm Request in these Aggregate Resv.
(6) The Aggregator merely complies with the received ResvConfirm
Request and returns the corresponding Aggregate ResvConfirm.
Moreover, the PCN-ingress-node functionality uses the PCN object
to map the RSVP generic aggregated reservation state onto the
maintained PCN ingress-egress-aggregate state. Moreover, the
Aggregator performs the steps specified in Section 3.11.
(7) The Deaggregator has explicit confirmation that both Aggregate
Resvs are established.
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(8) On receipt of the e2e Resv, the Deaggregator applies the mapping
policy defined by the network administrator to map the e2e Resv
onto a generic aggregate reservation. Let's assume that this
policy is such that the e2e reservation is to be mapped onto the
generic aggregate reservation with PHB-ID=x. The Deaggregator
knows that a generic aggregate reservation (GAx) is in place for
the corresponding PHB-ID since (7). The Deaggregator performs
admission control of the e2e Resv onto the generic aggregate
reservation for PHB-ID=x (GAx). Assuming that the generic
aggregate reservation for PHB-ID=x (GAx) had been established
with sufficient bandwidth to support the e2e Resv, the
Deaggregator adjusts its counter, tracking the unused bandwidth
on the generic aggregate reservation. Then it forwards the e2e
Resv to the Aggregator including a SESSION-OF-INTEREST object
conveying the selected mapping onto GAx (and hence onto
PHB-ID=x).
(9) The Aggregator records the mapping of the e2e Resv onto GAx (and
onto PHB-ID=x). The Aggregator removes the SOI object and
forwards the e2e Resv towards the sender.
11. Authors' Address
Georgios Karagiannis
University of Twente
P.O. Box 217
7500 AE Enschede,
The Netherlands
EMail: g.karagiannis@utwente.nl
Anurag Bhargava
Cisco Systems, Inc.
7100-9 Kit Creek Road
PO Box 14987
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27709-4987
USA
Email: anuragb@cisco.com
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