Generic Aggregate RSVP Reservations February 2006 Internet Draft Francois Le Faucheur Bruce Davie Cisco Systems, Inc. Pratik Bose Lockheed Martin Chris Christou Michael Davenport Booz Allen Hamilton draft-ietf-tsvwg-rsvp-ipsec-00.txt Expires: August 2006 February 2006 Generic Aggregate RSVP Reservations draft-ietf-tsvwg-rsvp-ipsec-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract [RSVP-AGG] defines aggregate RSVP reservations allowing resources to be reserved in a Diffserv network for a given DSCP from a given source to a given destination. [RSVP-AGG] also defines how end-to-end Le Faucheur, et al. [Page 1]
Generic Aggregate RSVP Reservations February 2006 RSVP reservations can be aggregated onto such aggregate reservations when transiting through a Diffserv cloud. There are situations where multiple such aggregate reservations are needed for the same source IP address, destination IP address and DSCP. However, this is not supported by the aggregate reservations defined in [RSVP-AGG]. In order to support this, the present document defines a more flexible type of aggregate RSVP reservations, referred to as generic aggregate reservation. Multiple such generic aggregate reservations can be established for a given DSCP from a given source IP address to a given destination IP address. The generic aggregate reservations may be used to aggregate end-to-end RSVP reservations. This document also defines the procedures for such aggregation. The generic aggregate reservations may also be used end-to-end directly by end-systems attached to a Diffserv network. Copyright Notice Copyright (C) The Internet Society (2006). Specification of Requirements 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 [RFC2119]. 1. Introduction [RSVP-AGG] defines RSVP aggregate reservations allowing resources to be reserved in a Diffserv network for a flow characterized by its 3- tuple <source IP address, destination IP address, DSCP>. [RSVP-AGG] also defines the procedures for aggregation of end-to-end RSVP reservations onto such aggregate reservations when transiting through a Diffserv cloud. Such aggregation is illustrated in Figure 1. -------------------------- / Aggregation \ |----| | Region | |----| H--| R |\ |-----| |------| /| R |-->H H--| |\\| | |---| |---| | |//| |-->H |----| \| | | I | | I | | |/ |----| | Agg |======================>| Deag | /| | | | | | | |\ H--------//| | |---| |---| | |\\-------->H H--------/ |-----| |------| \-------->H | | Le Faucheur, et al. [Page 2]
Generic Aggregate RSVP Reservations February 2006 \ / -------------------------- H = Host requesting end-to-end RSVP reservations R = RSVP router Agg = Aggregator Deag = Deaggregator I = Interior Router --> = E2E RSVP reservation ==> = Aggregate RSVP reservation Figure 1 : Aggregation of E2E Reservations over aggregate RSVP Reservations These aggregate reservations use a SESSION type specified in [RSVP- AGG] that contains the receiver (or Deaggregator) IP address and the DSCP of the PHB from which Diffserv resources are to be reserved. For example, in the case of IPv4, the SESSION object is specified as: o IP4 SESSION object: Class = SESSION, C-Type = RSVP-AGGREGATE-IP4 +-------------+-------------+-------------+-------------+ | IPv4 Session Address (4 bytes) | +-------------+-------------+-------------+-------------+ | /////////// | Flags | ///////// | DSCP | +-------------+-------------+-------------+-------------+ These aggregate reservations use a SENDER_TEMPLATE and FILTER_SPEC types specified in [RSVP-AGG] and which contains only the sender (or Aggregator) IP address. For example, in the case of IPv4, the SENDER_TEMPLATE is specified as: o IP4 SENDER_TEMPLATE object: Class = SENDER_TEMPLATE, C-Type = RSVP-AGGREGATE-IP4 +-------------+-------------+-------------+-------------+ | IPv4 Aggregator Address (4 bytes) | +-------------+-------------+-------------+-------------+ Thus it is possible to establish, from a given source IP address to a given destination IP address, separate such aggregate reservations for different DSCPs. However, from a given source IP address to a Le Faucheur, et al. [Page 3]
Generic Aggregate RSVP Reservations February 2006 given IP destination address, only a single [RSVP-AGG] aggregate reservation can be established for a given DSCP. Situations have since been identified where multiple such aggregate reservations are needed for the same source IP address, destination IP address and DSCP. One example is where E2E reservations using different preemption priorities (as per [RSVP-PREEMP]) need to be aggregated through a Diffserv cloud using the same DSCP. Using multiple aggregate reservations for the same DSCP allows enforcement of the different preemption priorities within the aggregation region. In turn this allows much more efficient management of the Diffserv resources and in period of resource shortage allows to sustain a larger number of E2E reservations with higher preemption priorities. For example, [SIG-NESTED] discusses in details how end-to-end RSVP reservations can be established in a nested VPN environment through RSVP aggregation. In particular, [SIG-NESTED] describes how multiple parallel generic aggregate reservations (for the same DSCP), each with different preemption priorities, can be used to efficiently support the preemption priorities of end-to-end reservations. This document addresses this requirement for multiple aggregate reservations for the same DSCP, by defining a more flexible type of aggregate RSVP reservations, referred to as generic aggregate reservations. This is achieved primarily by adding the notions of a Virtual Destination Port and of an Extended Virtual Destination Port in the RSVP Session object. The notion of Virtual Destination Port was introduced in [RSVP-IPSEC] to address a similar requirement (albeit in a different context) for identification and demultiplexing of sessions beyond the IP destination address. This document reuses this notion from [RSVP- IPSEC] for identification and demultiplexing of generic aggregate sessions beyond the IP destination address and DSCP. This allows multiple generic aggregate reservations to be established for a given DSCP, from a given source IP address to a given destination IP address. [RSVP-TE] introduced the concept of an Extended Tunnel ID (in addition to the tunnel egress address and the Tunnel ID) in the Session object used to establish MPLS Traffic Engineering tunnels with RSVP. The Extended Tunnel ID provides a very convenient mechanism for the tunnel ingress node to narrow the scope of the session to the ingress-egress pair. The ingress node can achieve this by using one of its own IP addresses as a globally unique identifier and including it in the Extended Tunnel ID and therefore within the Session object. This document reuses this notion of Extended Tunnel ID from [RSVP-TE], simply renaming it Extended Virtual Destination Le Faucheur, et al. [Page 4]
Generic Aggregate RSVP Reservations February 2006 Port, in order to provide a convenient mechanism to narrow the scope of an generic aggregate session to an Aggregator-Deaggregator pair. The generic aggregate reservations may be used to aggregate end-to- end RSVP reservations. This document also defines the procedures for such aggregation. These procedures are based on those of [RSVP-AGG] and this document only specifies the differences with those. The generic aggregate reservations may also be used end-to-end directly by end-systems attached to a Diffserv network. 1.1. Related RFCs and Internet-Drafts This document is heavily based on [RSVP-AGG]. It reuses [RSVP-AGG] wherever applicable and specifies the necessary extensions beyond [RSVP-AGG]. The mechanisms defined in [BW-REDUC] allow an existing reservation to be reduced in allocated bandwidth in lieu of tearing that reservation down. These mechanisms are applicable to the generic aggregate reservations defined in the present document. [RSVP-TUNNEL] describes a general approach to running RSVP over various types of tunnels. One of these types of tunnel, referred to as a "type 2 tunnel", has some similarity with the generic aggregate reservations described in this document. The similarity stems from the fact that a single, aggregate reservation is made for the tunnel while many individual flows are carried over that tunnel. However, [RSVP-TUNNEL] does not address the use of Diffserv-based classification and scheduling in the core of a network (between tunnel endpoints), but rather relies on a UDP/IP tunnel header for classification. This is why [RSVP-AGG] required additional objects and procedures beyond those of [RSVP-TUNNEL]. Like [RSVP-AGG], this document also assumes the use of Diffserv-based classification and scheduling in the aggregation region and, thus, requires additional objects and procedures beyond those of [RSVP-TUNNEL]. As explained in section 1, this document reuses the notion of Virtual Destination Port from [RSVP-IPSEC] and the notion of Extended Tunnel ID from [RSVP-TE]. 1.2. Organization Of This Document Section 2 defines the new RSVP objects related to generic aggregate reservations. Section 3 describes the processing rules for handling of generic aggregate reservations. Section 4 specifies the procedures for aggregation of end to end RSVP reservations over generic Le Faucheur, et al. [Page 5]
Generic Aggregate RSVP Reservations February 2006 aggregate RSVP reservations. Finally Section 5 provides example usage of how the generic aggregate reservations may be used. The IANA Considerations and the Security Considerations are discussed in Section 6 and 7, respectively. 1.3. Change History 1.3.1. Changes From draft-lefaucheur-rsvp-ipsec-02 To draft-ietf-tsvwg- rsvp-ipsec-00 The most significant changes are: o de-correlate the generic aggregate reservations from IPsec operations, in line with comments from the Security experts review. This significantly affects (and simplifies considerably) the document in many places. o add the notion of Extended Virtual Destination port (reusing the notion of Extended Tunnel ID of [RSVP-TE]). o added recommendations on use of IP addresses by Aggregator and Deaggregator 1.3.2. Changes From draft-lefaucheur-rsvp-ipsec-01 To draft-lefaucheur- rsvp-ipsec-02 The most significant changes are: o added text in section 4.2 about Aggregator/Deaggregator responsibilities with respect to mapping of end-to-end reservations onto aggregate reservations. The text also clarified that DCLASS object is no longer needed in PathErr message requesting new Aggregate Reservations o Moved the text discussing details of the procedures to handle dynamic update of SPI values from Security Considerations section into a new section 4.4. o updates to Security Considerations section to start addressing some comments from Security experts review. 1.3.3. Changes From draft-lefaucheur-rsvp-ipsec-00 To draft-lefaucheur- rsvp-ipsec-01 The most significant change is the broadening of the applicability of the new type of aggregate reservations beyond use for Aggregate reservations for IPsec tunnels (to environments where IPsec is not Le Faucheur, et al. [Page 6]
Generic Aggregate RSVP Reservations February 2006 used). This affects the document in multiple places including the following changes: o document renamed to "Generic Aggregate RSVP Reservations" o added a subsection in Introduction to discuss a case where Generic Aggregate RSVP Reservations are needed in non IPsec environments o added text about the fact that the Generic Aggregate Reservations can be used with IP-in-IP and GRE encapsulation (in addition to with IPsec AH and ESP) o added example usage under Section 5 for environment where IPsec is not used The other significant changes are: o added a subsection on the changes of the [RSVP-AGG] procedures under Section 4 o added explanation about allocation of VDstPort values by Deaggregator, in that same subsection o added value of Protocol ID in all example generic aggregate reservations in Section 5 2. Object Definition This document defines two new objects under the SESSION Class and a new object under a new AGGREGATION SESSION Class. It reuses the RSVP-AGGREGATE-IP4 FILTER_SPEC, RSVP-AGGREGATE-IP6 FILTER_SPEC, RSVP-AGGREGATE-IP4 SENDER_TEMPLATE and RSVP-AGGREGATE- IP6 SENDER_TEMPLATE objects defined in [RSVP-AGG]. 2.1. SESSION Class o GENERIC-AGGREGATE-IPv4 SESSION object: Class = 1 C-Type = To be allocated by IANA 0 7 8 15 16 23 24 31 +-------------+-------------+-------------+-------------+ | IPv4 DestAddress (4 bytes) | +-------------+-------------+-------------+--+----------+ | Reserved | Flags | vDstPort |Rd| DSCP | Le Faucheur, et al. [Page 7]
Generic Aggregate RSVP Reservations February 2006 +-------------+-------------+-------------+--+----------+ | Extended vDstPort | +-------------+-------------+-------------+-------------+ 0 7 8 15 16 23 24 31 IPv4 DestAddress (IPv4 Destination Address) IPv4 address of the receiver (or Deaggregator) Reserved A 8-bit field. All bits MUST be set to 0 on transmit. This field MUST be ignored on receipt. VDstPort (Virtual Destination Port) An 8-bit identifier used in the SESSION that remains constant over the life of the generic aggregate reservation. Rd (Reserved) A 2-bit field. All bits MUST be set to 0 on transmit. This field MUST be ignored on receipt. DSCP (Diffserv Code Point) A 6-bit field containing the DSCP of the PHB from which Diffserv resources are to be reserved. Extended vDstPort (Extended Virtual Destination Port) A 32-bit identifier used in the SESSION that remains constant over the life of the generic aggregate reservation. Normally set to all zeros. A sender (or Aggregator) that wishes to narrow the scope of a SESSION to the sender-receiver pair (or Aggregator- Deaggregator pair) may place its IPv4 address here as a globally unique identifier. o GENERIC-AGGREGATE-IPv6 SESSION object: Class = 1 C-Type = To be allocated by IANA 0 7 8 15 16 23 24 31 +-------------+-------------+-------------+-------------+ Le Faucheur, et al. [Page 8]
Generic Aggregate RSVP Reservations February 2006 | | + + | | + IPv6 DestAddress (16 bytes) + | | + + | | +-------------+-------------+-------------+--+----------+ | Reserved | Flags | vDstPort |Rd| DSCP | +-------------+-------------+-------------+--+----------+ | | + + | Extended vDstPort | + + | (16 bytes) | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 0 7 8 15 16 25 26 31 IPv6 DestAddress (IPv6 Destination Address) IPv6 address of the receiver (or Deaggregator) Reserved A 8-bit field. All bits MUST be set to 0 on transmit. This field MUST be ignored on receipt. VDstPort (Virtual Destination Port) A 8-bit identifier used in the SESSION that remains constant over the life of the generic aggregate reservation. Rd (Reserved) A 2-bit field. All bits MUST be set to 0 on transmit. This field MUST be ignored on receipt. DSCP (Diffserv Code Point) A 6-bit field containing the DSCP of the PHB from which Diffserv resources are to be reserved Le Faucheur, et al. [Page 9]
Generic Aggregate RSVP Reservations February 2006 Extended vDstPort (Extended Virtual Destination Port) A 16-byte identifier used in the SESSION that remains constant over the life of the generic aggregate reservation. Normally set to all zeros. A sender (or Aggregator) that wishes to narrow the scope of a SESSION to the sender-receiver pair (or Aggregator- Deaggregator pair) may place its IPv6 address here as a globally unique identifier. 2.2. AGGREGATION-SESSION Class o IPv4-AGGREGATION-SESSION object: Class = To be allocated by IANA C-Type = To be allocated by IANA 0 7 8 15 16 23 24 31 +-------------+-------------+-------------+-------------+ | Length (bytes) | Class-Num | C-Type | +-------------+-------------+-------------+-------------+ | | // SESSION Object // | | +-------------+-------------+-------------+-------------+ o IPv6-AGGREGATION-SESSION object: Class = To be allocated by IANA (same as for IPv4-AGGREGATION-SESSION) C-Type = To be allocated by IANA 0 7 8 15 16 23 24 31 +-------------+-------------+-------------+-------------+ | Length (bytes) | Class-Num | C-Type | +-------------+-------------+-------------+-------------+ | | // SESSION Object // | | +-------------+-------------+-------------+-------------+ For example, if the AGGREGATION-SESSION object is used to indicate that the Aggregate Session needed is a GENERIC-AGGREGATE-IPv4 SESSION then the AGGREGATION-SESSION will be encoded like this: 0 7 8 15 16 23 24 31 +-------------+-------------+-------------+-------------+ | |IPv4-AGGR-SES|IPv4-AGGR-SES| Le Faucheur, et al. [Page 10]
Generic Aggregate RSVP Reservations February 2006 | Length (bytes) | Class-Num | C-Type | +-------------+-------------+-------------+-------------+ | IPv4 DestAddress (4 bytes) | +-------------+-------------+-------------+--+----------+ | Reserved | Flags | vDstPort | DSCP | +-------------+-------------+-------------+--+----------+ | Extended vDstPort | +-------------+-------------+-------------+-------------+ 0 7 8 15 16 23 24 31 3. Processing Rules For Handling Generic Aggregate RSVP Reservations This section presents additions to the Processing Rules presented in [RSVP-PROCESS]. These additions are required in order to properly process the GENERIC-AGGREGATE-IPv4 (resp. GENERIC-AGGREGATE-IPv6) SESSION object and the RSVP-AGGREGATE-IP4 (resp. RSVP-AGGREGATE-IP6) FILTER_SPEC object. Values for referenced error codes can be found in [RSVP]. As with the other RSVP documents, values for internally reported (API) errors are not defined. When referring to the new GENERIC-AGGREGATE-IPv4 and GENERIC- AGGREGATE-IPv6 SESSION objects, IP version will not be included and they will be referred to simply as GENERIC-AGGREGATE SESSION, unless a specific distinction between IPv4 and IPv6 is being made. When referring to the [RSVP-AGG] RSVP-AGGREGATE-IP4 and RSVP-AGGREGATE-IP6 SESSION, FILTER_SPEC and SENDER_TEMPLATE objects, IP version will not be included and they will be referred to simply as RSVP-AGGREGATE, unless a specific distinction between IPv4 and IPv6 is being made. 3.1. Required Changes to Path and Resv Processing Both RESV and PATH processing will need to be changed to support the new objects. The following PATH message processing changes are required: o When a session is defined using the GENERIC-AGGREGATE SESSION object, only the [RSVP-AGG] RSVP-AGGREGATE SENDER_TEMPLATE may be used. When this condition is violated in a PATH message received by an RSVP end-station, the RSVP end-station SHOULD report a "Conflicting C-Type" API error to the application. When this condition is violated in a PATH message received by an RSVP router, the RSVP router MUST consider this as a message formatting error. Le Faucheur, et al. [Page 11]
Generic Aggregate RSVP Reservations February 2006 o For PATH messages that contain the GENERIC-AGGREGATE SESSION object, the VDstPort value, the Extended VDstPort value and the DSCP value should be recorded (in addition to the destination/Deaggregator address and source/aggregator address). These values form part of the recorded state of the session. The DSCP may need to be passed to traffic control; however the vDstPort and Extended VDstPort are not passed to traffic control since they do not appear inside the data packets of the corresponding reservation. The changes to RESV message processing are: o When a RESV message contains a [RSVP-AGG] RSVP-AGGREGATE FILTER_SPEC, the session MUST be defined using either the RSVP-AGGREGATE SESSION object (as per [RSVP-AGG]) or the GENERIC-AGGREGATE SESSION object (as per this document). If this condition is not met, an RSVP router or end-station MUST consider that there is a message formatting error. o When the RSVP-AGGREGATE FILTER_SPEC is used and the SESSION type is GENERIC-AGGREGATE, each node MAY have a data classifier installed for the flow: * If the node needs to perform fine-grain classification (for example to perform fine-grain policing on ingress at a trust boundary) then the node MUST create a data classifier described by the 3-tuple <DestAddress, SrcAddress, DSCP>. Note that if multiple reservations are established with different Virtual Destination Ports (and/or different Extended Virtual Destination Ports) but with the same <DestAddress, SrcAddress, DSCP>, then those cannot be distinguished by the classifier. If the router is using the classifier for policing purposes, the router will therefore police those together and MUST program the policing rate to the sum of the reserved rate across all the corresponding reservations. * If the node only needs to perform Diffserv classification (for example inside the aggregation domain downstream of the trust boundary) then the node MUST rely on the Diffserv data classifier based on the DSCP only. 4. Procedures for Aggregation over Generic Aggregate RSVP Reservations The procedures for Aggregation of E2E Reservations over Generic Aggregate RSVP Reservations are the same as the procedures specified Le Faucheur, et al. [Page 12]
Generic Aggregate RSVP Reservations February 2006 in [RSVP-AGG] with the exceptions of the procedure changes listed in this section. As specified in [RSVP-AGG], the Deaggregator is responsible for mapping a given E2E reservation on a given aggregate reservation. The Deaggregator requests establishment of a new aggregate reservation by sending to the Aggregator an E2E PathErr message with an error code of NEW-AGGREGATE-NEEDED. In [RSVP-AGG], the Deaggregator conveys the DSCP of the new requested aggregate reservation by including a DCLASS Object in the E2E PathErr and encoding the corresponding DSCP inside. This document modifies and extends this procedure. The Deaggregator MUST include in the E2E PathErr message an AGGREGATION-SESSION object which contains the Session to be used for establishment of the requested generic aggregate reservation. Since the AGGREGATION- SESSION object contains the DSCP, the DCLASS object need not be included in the PathErr message. Note that the Deaggregator can easily ensure that different Aggregators use different sessions for their Aggregate Path towards a given Deaggregator. This is because the Deaggregator can easily select VDstPort and/or Extended VDstPort numbers which are different for each Aggregator (for example by using the Aggregator address as the Extended VDstPort) and can communicate those inside the AGGREGATION-SESSION object. This provides an easy solution to establish separate reservations from every Aggregator to a given Deaggregator. Conversely, if reservation sharing were needed across multiple Aggregators, the Deaggregator could facilitate this by allocating the same VDstPort and Extended VDstPort to the multiple Aggregators and thus including the same AGGREGATION-SESSION object in the E2E PathErr messages sent to these Aggregators. The Aggregators could then all establish an Aggregate Path with the same Session. Therefore various sharing scenarios can easily be supported. Policies followed by the Deaggregator to determine which aggregators need shared or separate reservations are beyond the scope of this document. The Deaggregator MAY also include in the E2E PathErr message (with an error code of NEW-AGGREGATE-NEEDED) additional RSVP objects which are to be used for establishment of the new needed generic aggregate reservation. For example, the Deaggregator MAY include in the E2E PathErr an RSVP Signaled Preemption Priority Policy Element (as specified in [RSVP-PREEMP]. The [RSVP-AGG] procedures for processing of an E2E PathErr message with an error code of NEW-AGGREGATE-NEEDED by the Aggregator are extended correspondingly. On receipt of such a message containing an AGGREGATION-SESSION object, the Aggregator MUST use the Session provided in the AGGREGATION-SESSION object to trigger establishment of a generic aggregate reservation. The Aggregator MUST use the Le Faucheur, et al. [Page 13]
Generic Aggregate RSVP Reservations February 2006 DestAddress found in the AGGREGATION-SESSION object as the destination of the Aggregate Path. When an RSVP Signaled Preemption Priority Policy Element is contained in the received E2E PathErr message, the Aggregator MUST include this object in the Aggregate Path for the corresponding generic aggregate reservation. When other additional objects are contained in the received E2E PathErr message and those can be unambiguously interpreted as related to the new needed generic aggregate reservation (as opposed to related to the E2E reservation), the Aggregator SHOULD include those in the Aggregate Path for the corresponding generic aggregate reservation. The Aggregator MUST use as the Source Address (i.e. as the Aggregator Address) for the generic aggregate reservation, the address it uses to identify itself as the PHOP when forwarding the E2E Path messages corresponding to the E2E PathErr message. The Deaggregator follows the same procedures as described in [RSVP- AGG] for establishing, maintaining and clearing the aggregate Resv state. However, in this document, the Deaggregator MUST use the generic aggregate reservations and hence use the GENERIC-AGGREGATE SESSION specified earlier in this document. This document also modifies the procedures of [RSVP-AGG] related to exchange of E2E Resv messages between Deaggregator and Aggregator. The Deaggregator MUST include the new AGGREGATION-SESSION object in the E2E Resv message, in order to convey to the Aggregator which aggregate session to map a given E2E reservation onto. Again, since the AGGREGATION-SESSION object contains the DSCP, the DCLASS object need not be included in the E2E Resv message. The Aggregator MUST interpret the AGGREGATION-SESSION object in the E2E Resv as indicating which generic aggregate reservation session the corresponding E2E reservation is mapped onto. [RSVP-AGG] describes how the Aggregator and Deaggregator can communicate their respective identity to each other. For example the Aggregator includes one of its IP addresses in the RSVP HOP object in the E2E Path which is transmitted downstream and received by the Deaggregator once it traversed the aggregation region. Similarly, the Deaggregator identifies itself to the Aggregator by including one of its IP addresses in various fields, including the ERROR SPECIFICATION of the E2E PathErr message (containing the NEW-AGGREGATE-NEEDED Error Code), in the AGGREGATION-SESSION object included in the same E2E PathErr message and in the RSVP HOP object of the E2E Resv message. However, [RSVP-AGG] does not discuss which IP addresses are to be selected by the aggregator and Deaggregator for such purposes. Because these addresses are intended to identify the Aggregator and Deaggregator and not to identify any specific interface on these devices, this document RECOMMENDS that the Aggregator and Deaggregator SHOULD use interface-independent addresses (for example a loopback address) whenever they communicate their respective Le Faucheur, et al. [Page 14]
Generic Aggregate RSVP Reservations February 2006 identity to each other. This ensures that respective identification of the Aggregator and Deaggregator by any interface state change on these devices. In turns this results in more stable operations and considerably reduced RSVP signaling in the aggregation region. For example, if interface-independent addresses are used by the Aggregator and the Deaggregator, then a failure of an interface on these devices may simply result in the rerouting of a given generic aggregate reservation but will not result in the generic aggregate reservation having to be torn down and another one established, nor will it result in a change of mapping of E2E reservations on generic aggregate reservations (assuming the Aggregator and Deaggregator still have reachability after the failure and the Aggregator and Deaggregator are still on the shortest path to the destination). However, when identifying themselves to real RSVP neighbors (i.e. neighbors which are not on the other side of the aggregation region), the Aggregator and Deaggregator SHOULD continue using interface- dependent addresses as per regular [RSVP] procedures. This applies for example when the Aggregator identifies itself downstream as a PHOP for the generic aggregate reservation or identifies itself upstream as a NHOP for an E2E reservation. This also applies when the Deaggregator identifies itself downstream as a PHOP for the E2E reservation or identifies itself upstream as a NHOP for the generic aggregate reservation. As part of the processing of generic aggregate reservations, interior routers (i.e. routers within the aggregation region) SHOULD continue using interface-dependent address as per regular [RSVP] procedures. More generally, within the aggregation region (ie between Aggregator and Deaggregator) the operation of RSVP should be modeled with the notion that E2E reservations are mapped to aggregate reservations and are no longer tied to physical interfaces (as was the case with regular RSVP). However, generic aggregate reservations (within the aggregation region) as well as E2E reservations outside the aggregation region, retain the model of regular RVSP and remain tied to physical interfaces. 5. Example Usage Of Multiple Generic Aggregate Reservations Per DSCP From a Given Aggregator to a Given Deaggregator Let us consider the environment depicted in Figure 2 below. RSVP aggregation is used to support E2E reservations between Cloud-1, Cloud-2 and Cloud-3. I----------I I----------I I Cloud-1 I I Cloud-2 I I----------I I----------I Le Faucheur, et al. [Page 15]
Generic Aggregate RSVP Reservations February 2006 | | Agg-Deag-1------------ Agg-Deag-2 / \ / Aggregation | | Region | | | | ---/ \ / \Agg-Deag-3---------/ | I----------I I Cloud-3 I I----------I Figure 2 : Example Usage of Generic Aggregate IP Reservations Let us assume that: o the E2E reservations from Cloud-1 to Cloud-3 have a preemption of either P1 or P2 o the E2E reservations from Cloud-2 to Cloud-3 have a preemption of either P1 or P2 o the E2E reservations are only for Voice (which needs to be treated in the aggregation region using the EF PHB) o traffic from the E2E reservations is encapsulated in Aggregate IP reservations from Aggregator to Deaggregator using GRE tunneling ([GRE]). Then, the following generic aggregate RSVP reservations may be established from Agg-Deag-1 to Agg-Deag-3 for aggregation of the end- to-end RSVP reservations: A first generic aggregate reservation for aggregation of Voice reservations from Cloud-1 to Cloud-3 requiring use of P1: * GENERIC-AGGREGATE-IPv4 SESSION= IPv4 DestAddress= Agg-Deag-3 vDstPort=V1 DSCP=EF Extended VDstPort= Agg-Deag-1 * STYLE=FF or SE * IPv4/GPI FILTER_SPEC= Le Faucheur, et al. [Page 16]
Generic Aggregate RSVP Reservations February 2006 IPv4 SrcAddress= Agg-Deag-1 * POLICY_DATA (PREEMPTION_PRI)=P1 A second generic aggregate reservation for aggregation of Voice reservations from Cloud-1 to Cloud-3 requiring use of P2: * GENERIC-AGGREGATE-IPv4 SESSION=Agg-Deag-3/V2/EF IPv4 DestAddress= Agg-Deag-3 vDstPort=V2 DSCP=EF Extended VDstPort= Agg-Deag-1 * STYLE=FF or SE * IPv4/GPI FILTER_SPEC IPv4 SrcAddress= Agg-Deag-1 * POLICY_DATA (PREEMPTION_PRI)=P2 where V1 and V2 are arbitrary VDstPort values picked by Agg-Deag-3. The following generic aggregate RSVP reservations may be established from Agg-Deag-2 to Agg-Deag-3 for aggregation of the end-to-end RSVP reservations: A third generic aggregate reservation for aggregation of Voice reservations from Cloud-2 to Cloud-3 requiring use of P1: * GENERIC-AGGREGATE-IPv4 SESSION IPv4 DestAddress= Agg-Deag-3 vDstPort=V3 DSCP=EF Extended VDstPort= Agg-Deag-2 * STYLE=FF or SE * IPv4/GPI FILTER_SPEC IPv4 SrcAddress= Agg-Deag-2 * POLICY_DATA (PREEMPTION_PRI)=P1 A fourth generic aggregate reservation for aggregation of Voice reservations from Cloud-2 to Cloud-3 requiring use of P2: * GENERIC-AGGREGATE-IPv4 SESSION IPv4 DestAddress= Agg-Deag-3 vDstPort=V4 DSCP=EF Le Faucheur, et al. [Page 17]
Generic Aggregate RSVP Reservations February 2006 Extended VDstPort= Agg-Deag-2 * STYLE=FF or SE * IPv4/GPI FILTER_SPEC=Agg-Deag-2 IPv4 SrcAddress= Agg-Deag-2 * POLICY_DATA (PREEMPTION_PRI)=P2 where V1 and V4 are arbitrary VDstPort values picked by Agg-Deag-3. Note that V3 and V4 could be equal to V1 and V2 since, in this example, the Extended VDstPort of the GENERIC-AGGREGATE Session contains the address of the Deaggregator and, thus, ensures that different sessions are used for each Deaggregator. 6. Security Considerations The security considerations associated with the RSVP protocol [RSVP] apply to this document as it relies on RSVP. When generic aggregate reservations are used for aggregation of E2E reservations, the security considerations discussed in [RSVP-AGG] apply. The security considerations discussed in [SIG-NESTED] apply when the generic aggregate reservations are used in the presence of IPsec gateways. 7. IANA Considerations This document requests that IANA allocates two new C-Types under the Class 1 for the two new RSVP objects (GENERIC-AGGREGATE-IPv4 SESSION and GENERIC-AGGREGATE-IPv6 SESSION) defined in section 2.1. This document also requests that IANA allocates one new Class-Num and two new C-Types for the two new RSVP objects (IPv4-AGGREGATION- SESSION and IPv6-AGGREGATION-SESSION) defined in section 2.2. 8. Acknowledgments This document borrows heavily from [RSVP-AGG]. It also borrows the concepts of Virtual Destination Port and Extended Virtual Destination Port respectively from [RSVP-IPSEC] and [RSVP-TE]. Also, we thank Fred Baker, Roger Levesque, Carol Iturralde, Daniel Le Faucheur, et al. [Page 18]
Generic Aggregate RSVP Reservations February 2006 Voce and Anil Agarwal for their input into the content of this document. Thanks to Steve Kent for insightful comments on usage of RSVP reservations in IPsec environments. 9. Normative References [RSVP] "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", Braden et al, RFC2205 [RSVP-IPSEC] "RSVP Extensions for IPsec Data Flows", Berger et al, RFC2207 [RSVP-AGG] "Aggregation of RSVP for IPv4 and IPv6 Reservations", Baker et al, RFC3175 [SIG-NESTED] "QoS Signaling in a Nested Virtual Private Network", Baker et al, draft-ietf-tsvwg-vpn-signaled-preemption-00.txt, work in progress [RSVP-PROCESS] "Resource ReSerVation Protocol (RSVP) -- Version 1 Message Processing Rules", Braden et al, RFC2209 [IPSEC-ARCH] "Security Architecture for the Internet Protocol", Kent et al, RFC2401 [DS-TUNNEL] "Differentiated Services and Tunnels", Black, RFC2983 [GRE] Generic Routing Encapsulation (GRE). Farinacci et al, RFC 2784 10. Informative References [BW-REDUC] "A Resource Reservation Extension for the Reduction of andwidth of a Reservation Flow", Polk et al, draft-polk-tsvwg-rsvp- bw-reduction-01.txt, work in progress [RSVP-TUNNEL] "RSVP Operation Over IP Tunnels", Terzis et al., RFC 2746, January 2000. [RSVP-PREEMP] Herzog, S., "Signaled Preemption Priority Policy Element", RFC 3181, October 2001. [RSVP-TE] Awduche et al, RSVP-TE: Extensions to RSVP for LSP Tunnels, RFC 3209, December 2001. 11. Authors Address: Le Faucheur, et al. [Page 19]
Generic Aggregate RSVP Reservations February 2006 Francois Le Faucheur Cisco Systems, Inc. Village d'Entreprise Green Side - Batiment T3 400, Avenue de Roumanille 06410 Biot Sophia-Antipolis France Email: flefauch@cisco.com Bruce Davie Cisco Systems, Inc. 300 Beaver Brook Road Boxborough, MA 01719 USA Email: bdavie@cisco.com Pratik Bose Lockheed Martin 22300 Comsat Drive Clarksburg, MD 20814 USA Email: pratik.bose@lmco. com Christou Christou Booz Allen Hamilton 8283 Greensboro Drive McLean, VA 22102 USA Email: christou_chris@bah.com Michael Davenport Booz Allen Hamilton 8283 Greensboro Drive McLean, VA 22102 USA Email: davenport_michael@bah.com 12. IPR Statements The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information Le Faucheur, et al. [Page 20]
Generic Aggregate RSVP Reservations February 2006 on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. 13. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 14. Copyright Notice Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Le Faucheur, et al. [Page 21]
