Internet Draft Gerald R. Ash
AT&T
Bilel Jamoussi
Nortel Networks
Young Lee
AT&T
Osama S. Aboul-Magd
Nortel Networks
February 1999
Expires: October 1999
QoS Resource Management in MPLS-Based Networks
<draft-ash-qos-routing-00.txt>
STATUS OF THIS MEMO:
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
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Distribution of this memo is unlimited.
COPYRIGHT NOTICE:
Copyright (C) The Internet Society (1999). All Rights Reserved.
ABSTRACT:
Efficient QoS resource management is needed for a host of existing and
ever-increasing new services. For service performance, flexibility, and
reduced cost it is preferable to provide integration of these services on a
shared network. Such integration and sharing is facilitated by QoS resource
management techniques described in the draft which are applicable to
MPLS-based networks. Such QoS resource management techniques are used in
PSTNs to standardize service classification, bandwidth allocation, bandwidth
protection, and priority routing treatment for all network services. In the
draft we illustrate the principles of QoS resource management and describe
their application to MPLS-based networks. In the proposed QoS resource
management method, bandwidth is allocated in discrete changes to each of
three virtual networks (VNs) corresponding to high-priority key services,
normal priority services, and best-effort lower priority services.
Bandwidth changes in VN bandwidth capacity are determined by edge
switch/routers based on an overall aggregated bandwidth demand for VN
capacity (not on a per-connection demand basis). Based on the aggregated
bandwidth demand, these edge switch/routers make periodic discrete changes
in bandwidth allocation, that is, either increase or decrease bandwidth on
the constraint-based routing label switched paths (CRLSPs) constituting the
VN bandwidth capacity. We propose to add optional parameters in the
constraint-based routing label distribution protocol (CRLDP) for QoS
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resource management. In particular, we propose an optional depth-of-search
(DoS) type/length/value (TLV) parameter in the CRLDP label request message
to control the bandwidth allocation on individual links in a CRLSP. In
addition, we propose an optional modify-TLV parameter in the CRLDP label
request message to allow modification of the assigned traffic parameters
(such as peak data rate, committed data rate, etc.) of an already existing
CRLSP. Finally, we propose a crankback-TLV parameter in the CRLDP
notification message to allow an edge switch/router to search out additional
alternate CRLSPs when a given CRLSP cannot accommodate a bandwidth request.
This draft addresses point-to-point QoS resource management, multipoint QoS
resource management is left for future study.
***************************************************************************
NOTE: A MICROSOFT WORD VERSION OF THIS DRAFT (WITH THE FIGURES) IS
AVAILABLE ON REQUEST
***************************************************************************
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Internet Draft QoS Resource Management in MPLS-Based Networks Feb 99
Table of Contents
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.0 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.0 QoS Resource Management . . . . . . . . . . . . . . . . . . . . 5
4.0 Summary of CRLDP Proposals . . . . . . . . . . . . . . . . . . 10
5.0 References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.0 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . 11
7.0 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 12
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QoS RESOURCE MANAGEMENT IN MPLS-BASED NETWORKS
1.0 Introduction
QoS resource management methods have been applied successfully in PSTNs over
the past decade [A98], and are recommended in this draft for QoS resource
management in IP multiprotocol label switching (MPLS)-based networks
[RCV99]. In the proposed QoS resource management method, bandwidth is
allocated in discrete changes to each of three virtual networks (VNs)
corresponding to high-priority key services, normal priority services, and
best-effort lower priority services. Examples of services within these VN
categories include a) key priority services such as defense voice
communication, b) normal priority services such as constant rate,
interactive, delay-sensitive voice; variable rate, interactive,
delay-sensitive IP-telephony; and variable rate, non-interactive,
non-delay-sensitive WWW file transfer, and c) lower priority best effort
services such as variable rate, non-interactive, non-delay-sensitive voice
mail, email, and file transfer. Bandwidth changes in VN bandwidth capacity
are determined by edge switch/routers based on an overall aggregated
bandwidth demand for VN capacity (not on a per-connection demand basis).
Based on the aggregated bandwidth demand, these edge switch/routers make
periodic discrete changes in bandwidth allocation, that is, either increase
or decrease bandwidth on the constraint-based routing label switched paths
(CRLSPs) constituting the VN bandwidth capacity.
In the draft we propose that the bandwidth allocation control for each VN
CRLSP be based on estimated bandwidth needs, bandwidth use, and status of
links in the CRLSP. The edge switch/router, or originating switch/router
(OSR), determines when VN bandwidth needs to be increased or decreased on a
CRLSP, and uses a proposed MPLS CRLSP bandwidth modification procedure to
execute needed bandwidth allocation changes on VN CRLSPs. In the bandwidth
allocation procedure the constraint-based routing label distribution
protocol (CRLDP) [J99, ADFF98] is used by specifying appropriate parameters
in the label request message to request bandwidth allocation changes on each
link in the CRLSP and to determined if link bandwidth can be allocated. If
a link bandwidth allocation is not allowed, a proposed CRLDP notification
message with crankback parameter allows the OSR to search out possible
bandwidth allocation on another CRLSP. In particular, we propose an
optional depth-of-search (DoS) type/length/value (TLV) parameter in the
CRLDP label request message to control the bandwidth allocation on
individual links in a CRLSP. In addition, we propose an optional
modify-TLV parameter in the CRLDP label request message to allow
modification of the assigned traffic parameters (such as peak data rate,
committed data rate, etc.) of an already existing CRLSP. Finally, we
propose a crankback-TLV parameter in the CRLDP notification message to allow
an edge switch/router to search out additional alternate CRLSPs when a given
CRLSP cannot accommodate a bandwidth request. This draft addresses
point-to-point QoS resource management, multipoint QoS resource management
is left for future study.
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2.0 Definitions
Link: a bandwidth transmission medium between switches that is
engineered as a unit;
Switch/router: a switching center or aggregation of switching centers
representing a network;
O-D pair: an originating switch/router to destination switch/router
pair for a given connection request;
Originating
switch/router: originating point within a given network;
Path: a concatenation of links providing a connection between an
O-D pair;
Route: a set of paths connecting the same O-D pair;
Routing table: describes the route choices and selection rules to select
one path out of the set for a connection request;
Terminating
switch/router: terminating point within a given network;
Traffic stream: a class of connections with the same traffic
characteristics;
Via
switch/router: a via point within a given network;
3.0 QoS Resource Management
Through the use of bandwidth allocation, reservation, and congestion control
techniques, QoS resource management can provide good network performance
under normal and abnormal operating conditions for all services sharing the
integrated network. In the multi-service, QoS resource management network,
bandwidth is allocated to the three individual VNs (high-priority key
services VN, normal priority services VN, and best-effort lower priority
services VN). This allocated bandwidth is protected as needed but otherwise
shared. Each OSR monitors VN bandwidth use on each VN CRLSP, and determines
when VN CRLSP bandwidth needs to be increased or decreased. Bandwidth
changes in VN bandwidth capacity are determined by OSRs based on an overall
aggregated bandwidth demand for VN capacity (not on a per-connection demand
basis). Based on the aggregated bandwidth demand, these OSRs make periodic
discrete changes in bandwidth allocation, that is, either increase or
decrease bandwidth on the CRLSPs constituting the VN bandwidth capacity. For
example, if connection requests are made for VN CRLSP bandwidth that exceeds
the current CRLSP bandwidth allocation, the OSR initiates a bandwidth
modification request on the appropriate CRLSP(s). This bandwidth
modification request may entail increasing the current CRLSP bandwidth
allocation by a discrete increment of bandwidth denoted here as
delta-bandwidth (DBW). DBW is a large enough bandwidth change so that
modification requests are made relatively infrequently. Also, the OSR
periodically monitors CRLSP bandwidth use, such as once each minute, and if
bandwidth use falls below the current CRLSP allocation the OSR initiates a
bandwidth modification request to decrease the CRLSP bandwidth allocation by
a unit of bandwidth such as DBW. In making a VN bandwidth allocation
modification, the OSR determines the QoS resource management parameters
including the VN priority (key, normal, or best-effort), VN
bandwidth-in-use, VN bandwidth allocation thresholds, and whether the CRLSP
is a first choice CRLSP or alternate CRLSP. A VN depth-of-search (DoS)
table determines a DoS load state threshold, or the "depth" to which network
capacity can be allocated, based on the QoS resource management parameters
for the VN bandwidth modification request.
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In using the DoS threshold to allocate VN bandwidth capacity, the OSR
selects a first choice CRLSP based on the routing table selection rules.
Path selection in the IP network may used open shortest path first (OSPF)
[M98, S95] for intra-domain routing. In OSPF-based layer 3 routing, as
illustrated in Figure 1, OSR A determines a list of shortest paths by using,
for example, Dijsktra's algorithm. This path list could be determined based
on administrative weights of each link, which are communicated to all
switches/routers within the autonomous system (AS) domain. These
administrative weights may be set, for example, to 1 + epsilon x distance,
where epsilon is a factor giving a relatively smaller weight to the distance
in comparison to the hop count. The OSR selects a path from the list based
on, for example, fixed routing (FR), time dependent routing (TDR), state
dependent routing (SDR), or event dependent routing (EDR) path selection
[A98]. For example, in using the first CRLSP A-B-E, OSR A sends CRLDP label
request message to via switch/router (VSR) B, which in turn forwards the
CRLDP label request message to terminating switch/router (TSR) E. VSR B and
TSR E are passed in the explicit routing CR/TLV parameter contained in the
CRLDP label request message. Each switch/router in the CRLSP reads the
CR/TLV information, and passes the CRLDP label request message to the next
switch/router listed in the CRLSP. If the first path is blocked at any of
the links in the path, a CRLDP notification message with a constraint-based
routing type/length/value (CR/TLV) crankback parameter is returned to OSR A
which can then attempt the next path. If FR is used, then this path is the
next path in the shortest path list, for example path A-C-D-E. If TDR is
used, then the next path is the next path in the routing table for the
current time period. If SDR is used, OSPF implements a distributed method
of flooding link status information, which is triggered either periodically
and/or by crossing load state threshold values. This method of distributing
link status information can be resource intensive and may not be any more
efficient than simpler path selection methods such as EDR. If EDR is used,
then the next path is the last successful path, and if that path is
unsuccessful another alternate path is searched out according to the EDR
path selection method.
Hence in using the selected CRLSP, the OSR sends the explicit routing, the
requested traffic parameters (peak data rate, committed data rate, etc.), an
optional DoS-TLV parameter, and an optional modify-TLV parameter in the
CRLDP label request message to each VSR and the TSR in the selected CRLSP.
Whether or not bandwidth can be allocated to the bandwidth modification
request on the first choice CRLSP is determined by each VSR applying the QoS
resource management rules. These rules entail that the VSR determine the
CRLSP link states (lightly loaded, heavily loaded, reserved, or busy), based
on bandwidth use and bandwidth available, and compare the link load state to
the DoS threshold sent in the CRLDP TLV parameters. If the first choice
CRLSP cannot be accessed, a VSR or TSR returns control to the OSR through
the use of a proposed crankback-TLV parameter in the CRLDP notification
message. At that point the OSR may then try an alternate CRLSP. Whether or
not bandwidth can be allocated to the bandwidth modification request on the
alternate path again is determined by the use of the DoS threshold compared
to the CRLSP link load state at each VSR. Priority queuing is used during
the time the connection is established, and at each link the queuing
discipline is maintained such that the packets are given priority according
to the VN traffic priority.
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In the proposed method of QoS resource management, the admission control for
bandwidth modification on each VN CRLSP is based on the status of the links
in the CRLSP. The OSR may select any CRLSP for which the first CRLSP link is
allowed according to QoS resource management criteria. If a subsequent
CRLSP link is not allowed, then a proposed CRLDP notification message with a
crankback-TLV parameter is used to return to the OSR and select an alternate
CRLSP. Determination of the CRLSP link load states is necessary for QoS
resource management to select network capacity on either the first choice
CRLSP or alternate CRLSPs. Four link load states are distinguished: lightly
loaded (LL), heavily loaded (HL), reserved (R), and busy (B). Selection of
CRLSP capacity uses a link state model and a depth-of-search (DoS) model to
determine if a bandwidth modification request can be admitted on a given
CRLSP. The allowed DoS load state threshold determines if a bandwidth
modification request can be admitted on a given link to an available
bandwidth "depth." In setting up the bandwidth modification request, the
OSR encodes the DoS load state threshold allowed on each link in the
proposed DoS-TLV parameter in the CRLDP label request. If a CRLSP link is
encountered at a VSR in which the idle link bandwidth and link load state
are below the allowed DoS load state threshold, then the VSR sends a CRLDP
notification message with a proposed crankback-TLV parameter to the OSR,
which can then route the bandwidth modification request to an alternate
CRLSP choice. For example, in Figure 1, CRLSP A-B-E may be the first path
tried where link A-B is in the LL state and link B-E is in the R state. If
the DoS load state allowed is HL or better, then the CRLSP bandwidth
modification request in the CRLDP label request message is routed on link
A-B but will not be admitted on link B-E, wherein the CRLSP bandwidth
modification request will be cranked back in the CRLDP notification message
to the originating switch A to try alternate CRLSP A-C-D-E. Here the CRLSP
bandwidth modification request succeeds since all links have a state of HL
or better.
The DoS load state threshold is a function of bandwidth-in-progress, service
priority, and bandwidth allocation thresholds, as follows:
Table 1. Determination of Depth-of-Search (DoS) Load State Threshold
------------------------------------------------------------------------------
Load State Key Normal Priority VN Best Effort
Allowed Priority VN ---------------------------------- Priority VN
First Choice CRLSP Alternate CRLSP
------------------------------------------------------------------------------
R if BWIPi <= if BWIPi <= BWavgi Not Allowed Note 1
2 * BWmaxi
HL if BWIPi <= if BWIPi <= BWmaxi if BWIPi <= Note 1
2 * BWmaxi BWavgi
LL All BWIPi All BWIPi All BWIPi Note 1
------------------------------------------------------------------------------
where
BWIPi = bandwidth-in-progress on VN i
BWavgi = minimum guaranteed bandwidth required for VN
i to carry the average offered bandwidth load
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BWmaxi = the bandwidth required for VN i to meet the blocking
probability grade-of-service objective for CRLSP
bandwidth allocation requests
= 1.1 x BWavgi
Note 1 = CRLSPs for the best effort priority VN are
allocated zero bandwidth; Diffserv queuing admits
best effort packets only if there is available
bandwidth on a link
Note that BWIP, BWavg, and BWmax are specified per OSR-TSR pair, and that
the QoS resource management method provides for a key priority VN, a normal
priority VN, and a best effort VN. Key services admitted by an OSR on the
key VN are given higher priority routing treatment by allowing greater path
selection DoS than normal services admitted on the normal VN. Best effort
services admitted on the best effort VN are given lower priority routing
treatment by allowing lesser path selection DoS than normal. The quantities
BWavgi are computed periodically, such as every week w, and can be
exponentially averaged over a several week period, as follows:
BWavgi(w) = .5 x BWavgi(w-1) + .5 x [ BWIPavgi(w) +
BWOVavgi(w) ]
BWIPavgi = average bandwidth-in-progress across a load
set period on VN i
BWOVavgi = average bandwidth allocation request
overflow across a load set period on VN i
where all variables are specified per OSR-TSR pair, and where BWIPi and
BWOVi are averaged across various load set periods, such as morning,
afternoon, and evening averages for weekday, Saturday, and Sunday, to
obtain BWIPavgi and BWOVavgi.
Illustrative values of the thresholds to determine link load states are as
follows:
Table 2. Determination of Link Load State
--------------------------------------------------
Name of State Condition
--------------------------------------------------
Busy B ILBWk < DBW
Reserved R ILBWk * Rthrk
Heavily Loaded HL Rthrk < ILBWk * HLthrk
Lightly Loaded LL HLthrk < ILBWk
--------------------------------------------------
where
ILBWk = idle link bandwidth on link k
DBW = delta bandwidth requirement for a bandwidth
allocation request
Rthrk = reservation bandwidth threshold for link k
= N x .05 x TBWk for bandwidth reservation
level N
HLthrk = heavily loaded bandwidth threshold for link
k
= Rthrk + .05 x TBWk
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TBWk = the total bandwidth required on link k to
meet the blocking probability
grade-of-service objective for bandwidth
allocation requests on their first choice
CRLSP.
QoS resource management implements bandwidth reservation logic to favor
connections routed on the first choice CRLSP in situations of link
congestion. If link blocking is detected, bandwidth reservation is
immediately triggered and the reservation level N is set for the link
according to the level of link congestion. In this manner bandwidth
allocation requests attempting to alternate-route over a congested link are
subject to bandwidth reservation, and the first choice CRLSP requests are
favored for that link. At the same time, the LL and HL link state
thresholds are raised accordingly in order to accommodate the reserved
bandwidth capacity N for the VN. Figure 2 illustrates bandwidth allocation
and the mechanisms by which bandwidth is protected through bandwidth
reservation. Under normal bandwidth allocation demands bandwidth is fully
shared, but under overloaded bandwidth allocation demands, bandwidth is
protected through the reservation mechanisms wherein each VN can use its
allocated bandwidth. Under failure, however, the reservation mechanisms
operate to give the key VN its allocated bandwidth before the normal
priority VN gets its bandwidth allocation. As noted on Table 1, the best
effort lower priority VN is not allocated bandwidth nor is bandwidth
reserved for the best effort VN. Illustrations are given in [A98] of the
robustness of dynamic bandwidth reservation in protecting the preferred
bandwidth requests across wide variations in traffic conditions.
The reservation level N (for example, N may have 1 of 4 levels), is
calculated for each link k based on the link blocking level of bandwidth
allocation requests. The link blocking level is equal to the total
requested but rejected (or overflow) link bandwidth allocation (measured in
total bandwidth), divided by the total requested link bandwidth allocation,
over the last periodic update interval, which is typically three minutes.
That is
BWOVk = total requested bandwidth allocation
overflow on link k
BWOFk = total requested or offered bandwidth
allocation on link k
LBLk = link blocking level on link k
= BWOVk/BWOFk
If LBLk exceeds a threshold value, the reservation level N is calculated
accordingly. The reserved bandwidth and link states are calculated based on
the total link bandwidth required on link k, TBWk, which is computed
on-line, for example every 1-minute interval m, and approximated as follows:
TBWk(m) = .5 x TBWk(m-1) +
.5 x [ 1.1 x TBWIPk(m) + TBWOVk(m) ]
TBWIPk = sum of the bandwidth in progress
(BWIPi) for all VNs i
for bandwidth requests on their
first choice CRLSP over link k
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TBWOVk = sum of bandwidth overflow (BWOVi) for all
VNs i for bandwidth requests on their
first choice CRLSP over link k
Therefore the reservation level and load state boundary thresholds are
proportional to the estimated required bandwidth load, which means that the
bandwidth reserved and the bandwidth required to constitute a lightly loaded
link rise and fall with the bandwidth load, as, intuitively, they should.
In addition to the QoS bandwidth management procedure for bandwidth
allocation requests, a QoS priority of service queuing capability is used
during the time connections are established on each of the three VNs. At
each link, a queuing discipline is maintained such that the packets being
served are given priority in the following order: key VN services, normal VN
services, and best effort VN services. Following the MPLS CRLSP bandwidth
allocation setup and the application of QoS resource management rules, the
priority of service parameter and label parameter need to be sent in each IP
packet, as illustrated in Figure 3. The priority of service parameter may be
included in the type of service (ToS), or differentiated services (diffserv)
[B98, ST98], parameter already in the IP packet header. Another possible
alternative is that the priority of service parameter might be included in
the MPLS label or "shim" appended to the IP packet (this is a matter for
further study). In either case, from the priority of service parameter, the
IP switch/router can determine the QoS treatment based on the QoS resource
management (priority queuing) rules for key VN packets, normal VN packets,
and best effort VN packets. From the label parameter, the IP switch/router
can determine the next switch/router to route the IP packet to as defined by
the MPLS protocol. In this way, the backbone switches/routers can have a
very simple per-packet processing implementation to implement QoS resource
management and MPLS routing.
4.0 Summary of CRLDP Proposals
In summary we make these proposals regarding CRLDP use in MPLS:
a) Edge switch/routers, or OSRs, monitor VN bandwidth use and decide
when to make CRLSP bandwidth modification requests. OSRs keep track of VN
priority, bandwidth-in-use, and bandwidth allocation thresholds and apply
DoS rules to determine the DoS threshold to apply for a bandwidth
modification request.
b) Backbone switch/routers, or VSRs, keep track of link state and
compare DoS threshold parameters to link state (as do OSRs).
c) OSRs formulate the CRLDP label request message, which carries the
explicit routing parameters specifying the VSRs and TSR in the selected
CRLSP, the optional DoS-TLV parameter specifying the allowed bandwidth
allocation threshold on each link in the CRLSP, and the optional modify-TLV
parameter to allow modification of the assigned traffic parameters (such as
peak data rate, committed data rate, etc.) of an already existing CRLSP.
d) VSRs or TSRs formulate the optional crankback-TLV parameter in the
CRLDP notification message, which specifies return of control of the link
bandwidth allocation request to the OSR, for possible further alternate
routing to search out additional alternate CRLSPs when a given CRLSP cannot
accommodate a bandwidth request.
This draft addresses point-to-point QoS resource management, multipoint QoS
resource management is left for future study.
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5.0 References
[A98] Ash, G. R., Dynamic Routing in Telecommunications Networks,
McGraw-Hill, 1998.
[ADFFT98] Anderson, L., Doolan, P., Feldman, N., Fredette, A., Thomas, B.,
LDP Specification, IETF draft-ietf-mpls-ldp-01.txt, August 1998.
[B98] Bernet, Y., et. al., A Framework for Differentiated Services, IETF
draft-ietf-diffserv-framework-01.txt, October 1998.
[J99] Jamoussi, B., Editor, Constraint-Based LSP Setup using LDP, IETF
draft-ietf-mpls-cr-ldp-01.txt, February 1999.
[M98] Moy, John, OSPF Version 2, IETF RFC 2328, April 1998.
[RVC99] Rosen, E., Viswanathan, A., Callon, R., Multiprotocol Label
Switching Architecture, IETF draft-ietf-mpls-arch-04.txt, February 1999.
[S95] Steenstrup, M., Editor, Routing in Communications Networks,
Prentice-Hall, 1995.
[ST98] Sikora, J., Teitelbaum, B., Differentiated Services for Internet 2,
Internet 2: Join Applications/Engineering QoS Workshop, Santa Clara, CA, May
1998.
6.0 Abbreviations
B Busy
BGP Border Gateway Protocol
BW Bandwidth
BWIP Bandwidth in Progress
BWOF Bandwidth Offered
BWOV Bandwidth Overflow
CRLDP Constraint-Based Routing Label Distribution Protocol
CRLSP Constraint-Based Routing Label Switched Path
DIFFSERV Differentiated Services
DoS Depth-of-Search
HL Heavily Loaded
IETF Internet Engineering Task Force
ILBW Idle Link Bandwidth
IP Internet Protocol
LBL Link Blocking Level
LDP Label Distribution Protocol
LL Lightly Loader
LSP Label Switched Path
MPLS Multiprotocol Label Switching
OSR Originating Switch/Router
OSPF Open Shortest Path First
PSTN Public Switched Telephone Network
QoS Quality of Service
R Reserved
TBW Total Bandwidth
TBWIP Total Bandwidth In Progress
TLV Type/Length/Value
ToS Type of Service
TSR Terminating Switch/Router
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VSR Via Switch/Router
VN Virtual Network
7.0 Authors' Addresses
Gerald R. Ash
AT&T
Room MT E3-3C37
200 Laurel Avenue
Middletown, NJ 07748
Phone: 732-420-4578
Fax: 732-440-6687
Email: gash@att.com
Bilel Jamoussi
Nortel Networks
P O Box 3511 Station C
Ottawa, ON K1Y 4H7
Canada
phone: +1 613 765-4814
Email: jamoussi@NortelNetworks.com
Young Lee
AT&T
Room MT E3-3A04
200 Laurel Avenue
Middletown, NJ 07748
Phone: 732-420-4477
Fax: 732-440-6697
Email: younglee@att.com
Osama S. Aboul-Magd
Nortel Networks
P O Box 3511 Station C
Ottawa, ON K1Y 4H7
Canada
phone: +1 613 763-5827
Email: osama@NortelNetworks.com
Figure 1 -- Label Switched Path Selection for Bandwidth Modification
Request
Figure 2 -- Bandwidth Management
Figure 3 -- IP Packet Structure under MPLS Switching
***************************************************************************
NOTE: A MICROSOFT WORD VERSION OF THIS DRAFT (WITH THE FIGURES) IS
AVAILABLE ON REQUEST
***************************************************************************
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