Internet DRAFT - draft-zhangm-ccamp-metric

draft-zhangm-ccamp-metric






Network Working Group                                           M. Zhang
Internet-Draft                                                   H. Ding
Intended status: Informational                                  YL. Zhao
Expires: April 24, 2012                                             BUPT
                                                               HY. Zhang
                                                                  YB. Xu
                                                                    CATR
                                                        October 22, 2011


Performance Metric of Convergence Time of Information Flooding in Multi-
                          Area GMPLS Networks
                      draft-zhangm-ccamp-metric-02

Abstract

   As one of the requirements of link state based routing protocols such
   as OSPF, link state update packets are intervally or reactively
   disseminate in the network in order to keep the information of
   topology and links resource synchronized at each control node.
   Considering large scale networks, massive messages are flooded in the
   control plane of General Multi-Protocol Label Switching (GMPLS) based
   multi-area networks.  The convergence time of link state based
   routing protocols will have a significant impact on the performance
   of the networks.  So measuring and analyzing the convergence time of
   information flooding in multi-areas becomes very important.  This
   document provides suggestions for measuring OSPF multi-area control
   plane convergence.  A performance metric of convergence time of
   information flooding is proposed to characterize the ability of
   information synchronization in multi-area networks.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on April 24, 2012.




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Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Motivations  . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Conventions Used in this Document  . . . . . . . . . . . . . .  4
   3.  Overview of the Performance metric . . . . . . . . . . . . . .  4
   4.  convergence time of information flooding in single area  . . .  4
     4.1.  Initial convergence time of information flooding . . . . .  4
       4.1.1.  Definition . . . . . . . . . . . . . . . . . . . . . .  4
       4.1.2.  Methodology  . . . . . . . . . . . . . . . . . . . . .  4
       4.1.3.  Sample . . . . . . . . . . . . . . . . . . . . . . . .  5
     4.2.  convergence time of information flooding with LSPs . . . .  6
       4.2.1.  Definition . . . . . . . . . . . . . . . . . . . . . .  6
       4.2.2.  Methodology  . . . . . . . . . . . . . . . . . . . . .  6
       4.2.3.  Sample . . . . . . . . . . . . . . . . . . . . . . . .  7
   5.  Convergence time of information flooding in multi-area
       networks . . . . . . . . . . . . . . . . . . . . . . . . . . .  7
     5.1.  Initial convergence time of information flooding . . . . .  7
       5.1.1.  Definition . . . . . . . . . . . . . . . . . . . . . .  8
       5.1.2.  Methodology  . . . . . . . . . . . . . . . . . . . . .  8
       5.1.3.  Sample . . . . . . . . . . . . . . . . . . . . . . . .  9
     5.2.  Convergence time of information flooding with LSPs . . . . 10
       5.2.1.  Definition . . . . . . . . . . . . . . . . . . . . . . 10
       5.2.2.  Methodology  . . . . . . . . . . . . . . . . . . . . . 11
       5.2.3.  Sample . . . . . . . . . . . . . . . . . . . . . . . . 12
   6.  Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 14
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 14
   8.  Acknowledgement  . . . . . . . . . . . . . . . . . . . . . . . 14
   9.  Normative References . . . . . . . . . . . . . . . . . . . . . 14
   Appendix A.  author  . . . . . . . . . . . . . . . . . . . . . . . 15
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15




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1.  Introduction

   GMPLS [RFC3945], which can handle multiple switching technologies:
   packet switching (PSC), Layer 2 switching (L2SC), Time-Division
   Multiplexing (TDM) Switching, wavelength switching (LSC) and fiber
   switching (FSC), is a key technology for transport and service
   networks.  As the network scale varies from time to time, division of
   the network is a natural solution to cope with large scale network
   control and management.  In order to keep the information of topology
   and links resource synchronized, which is necessary during the
   process of path computation, massive messages are necessary to be
   flooded in the control plane of multi-area networks.  So measuring
   and analyzing the convergence time of information flooding in multi-
   area networks becomes very important.  RFC 4061 provided suggestions
   for measuring OSPF single router control plane convergence.  However,
   performance metric in multi-area network are not specified in
   previous documents.

   In this document, we define a performance metric of convergence time
   of information flooding from the routing aspect to characterize the
   ability of information synchronization in multi-area networks.  The
   metric can be used to measure convergence time of information
   flooding in single area, multi-areas, initial and with LSPs.
   Methodologies and samples of the testing procedure for different
   scenarios are also included in the following sections.

1.1.  Motivations

   Convergence time of information flooding is useful for several
   reasons.

   o  When a large scale network is deployed, a series of tests are to
      be conducted to evaluate the network performance, such as adding
      or deleting the clients, establishing or tearing the connections,
      and so on.  The convergence time, which indicates the ability to
      synchronize the topology and link resource states, is also worth
      measuring and analyzing meantime, since it can further illustrate
      the reasonability of area division.

   o  During the operation, nodes or links failures may cause congestion
      due to both resource unavailability and a large amount of
      information flooding.  Measuring and monitoring convergence time
      of information flooding is helpful for network failure detection.

   o  After network updating and large scale reconfiguration,
      convergence time of information flooding should be measured,
      because it may reflect the reasonability of this updating by
      comparing the convergence time of information flooding with the



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      LSP setup delay.


2.  Conventions Used in this Document

   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].


3.  Overview of the Performance metric

   To evaluate the convergence performance of a GMPLS-based network from
   routing aspect, we define a performance metric of convergence time of
   information flooding.  The following sections specify the metric in
   different situations, initial or with LSPs, in single area or multi-
   areas.  The initial convergence time of information flooding measures
   the time that one network spends from its power-on to its full
   operation.  The convergence time with LSPs measures the time needed
   to synchronize the information after several changes in link resource
   states.  The convergence time in single area is intra-area time
   whereas the convergence time in multi-areas comprises intra-area time
   and inter-area time and the two kinds of convergence time need to
   compute separately.

   The convergence time of information flooding is either a real number
   of milliseconds or undefined.  And in methodology "undefined"
   convergence time is defined.


4.  convergence time of information flooding in single area

4.1.  Initial convergence time of information flooding

4.1.1.  Definition

   The initial convergence time of information flooding describes a
   period of time, which starts at the moment when the first bit of the
   first Hello packet is sent and ends at the moment when all nodes
   database synchronized in this area.

4.1.2.  Methodology

   Generally, the convergence time of initial information flooding in
   single area proceeds as follows,

   o  All control nodes in this area enable OSPF-TE;




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   o  Store a time structure, which records the first sending moment of
      Hello packets, in every control node.  And the starting point (T1)
      of the convergence time is the earliest sending moment among all
      control nodes in this area;

   o  After the neighbor relationships are established, Database
      Description (DD) packets are sent and received to synchronize the
      information topology and links resource according to RFC 2328.
      Then all nodes in the area are marked as full adjacency.  Store a
      time structure, which records the latest receiving moment of DD
      packets, in every node.  Choose the latest moment among all
      control nodes as end point (T2);

   o  Initial convergence time of information flooding in single area
      can be computed by subtracting the starting point from end point
      (T2-T1).

4.1.3.  Sample

   Initial information synchronization in single domain


   . . . . . . . . . . . . . . . .
   . +-----+  +-----+  +-----+   .
   . |NODE1|--|NODE2|--|NODE3|   .
   . +-----+  +-----+  +-----+   .
   .    |    /                   .
   . +-----+/    +-----+         .
   . |NODE4|-----|NODE5|         .
   . +-----+     +-----+         .
   .                             .
   .                     area    .
   . . . . . . . . . . . . . . . .

   Control nodes are represented by vertices and physical links are
   represented by dashed lines.  When all these control nodes enable
   OSPF-TE and their interfaces first become operational, Hello packets
   are flooded in this area to establish neighbor relationships as
   described in Section 7, RFC1583.

   For a area as shown in Figure 1, after the power-on, all five nodes
   begin to send and receive Hello packets.  In most occasions, these
   nodes receive the message in a very short interval which is normally
   a few microseconds.  So practically a structure of time is stored in
   every node to record the moment, which is the time when the node
   sends a Hello packet.  The starting point of the initial convergence
   time of information flooding is the earliest sending moment of all
   the Hello packets.



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   After the establishment of neighbor relationships, DD packets are
   sent and received to compare the nodes database so as to establish
   adjacency relationships.  And the receiving moments of DD packets
   should be stored in another time structure in every node.  Then
   choose the latest moment among all the receiving moments relating to
   DD packets as the end point of the convergence time of information
   flooding in this scenario.

   So the initial convergence time of information flooding in single
   area can be computed by subtracting the starting point from the end
   point.

4.2.  convergence time of information flooding with LSPs

4.2.1.  Definition

   The convergence time of information flooding with LSPs describes a
   time period, that starts at the moment when the ingress node sends
   the first bit of a Link State Update (LSU) packet and ends at the
   moment when the last node in this area receives the LSU packet.

   The undefined convergence time of information flooding with LSPs
   means ingress node fails to receive corresponding ResvConf message,
   which may indicates resource reservation failure or nodes breaking
   down along the LSP.

4.2.2.  Methodology

   Generally, the methodology proceeds as follows,

   o  All control nodes in this area enable OSPF-TE;

   o  Initial information synchronization is complete, which means all
      node Link State Database (LSDBs) are up-to-date;

   o  Select an ingress node ID0 and an egress node ID1, and create a
      LSP path from ID0 to ID1.

   o  Wait until ID0 receives the corresponding ResvConf message and
      updates its LSDB and forms a LSU packet LSU0.  Store a timestamp
      (T1) at ID0 as soon as possible;

   o  Another timestamp (T2) should be stored when the last node within
      this area receives LSU0 at the exact last node;

   o  The convergence time of information flooding with LSPs in single
      area can be computed by subtracting the two timestamps (T2-T1);




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   o  If ID0 fails to receive the corresponding ResvConf message in a
      reasonable period of time, the convergence time is set to
      undefined.

4.2.3.  Sample

   Convergence time of information flooding with LSPs in single area


   . . . . . . . . . . . . . . . .
   . +-----+  +-----+  +-----+   .
   . |NODE1|==|NODE2|==|NODE3|   .
   . +-----+  +-----+  +-----+   .
   .    ||   /                   .
   . +-----+/    +-----+         .
   . |NODE4|=====|NODE5|         .
   . +-----+     +-----+         .
   .                             .
   .                     area    .
   . . . . . . . . . . . . . . . .

   Control nodes are represented by vertices and physical links are
   represented by dashed lines, LSPs are represented by equal signs.
   For a single area as shown in Figure 2, NODE1->NODE2->NODE3
   constitute LSP1 which already exists, and NODE1->NODE4->NODE5
   constitute LSP2 which need to be measured.

   When NODE1, the ingress node of LSP2, receives a ResvConf message
   correspondingly with LSP2, it forms an LSU packet including changed
   LSAs and floods it within the area.  NODE2 and NODE4 receive the LSU
   and then NODE3 and NODE5 receive the message.  A time structure is
   stored in every control node to record the earliest sending moment
   and latest receiving moment of LSU packets.  The ingress node NODE1's
   sending moment can be the starting point and choose the latest moment
   among NODE2's, NODE3's, NODE4's, NODE5's receiving moments as the end
   point of the convergence time.

   So the convergence time of information flooding with LSPs in single
   area as depicted in Figure 2 can be computed by subtracting the
   starting point from the end point.


5.  Convergence time of information flooding in multi-area networks

5.1.  Initial convergence time of information flooding






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5.1.1.  Definition

   Initial convergence time of information flooding in multi-area
   network defines a time period, which starts at the moment when the
   first Hello packet is sent and ends at the moment when all nodes
   database synchronized in the network.

5.1.2.  Methodology

   Generally, convergence time of information flooding in multi-area
   network proceeds as follows,

   o  All control nodes in multi-areas enable OSPF-TE;

   o  Store a time structure, which records the first sending moment of
      Hello packets in every control node.  And the starting point (T1)
      of the convergence time is the earliest sending moment among all
      control nodes in the multi-area network;

   o  After the neighbor relationships are established, Database
      Description (DD) packets are sent and received to synchronize the
      information topology and links resource according to RFC 2328.
      Then all nodes in the area are marked as full adjacency.  Store a
      time structure, which records latest receiving moment of DD
      packets, in every node.  Choose the latest moment among all these
      structures as another timestamp (T2);

   o  Initial convergence time of information flooding in the multi-area
      network can be computed by subtracting the two timestamps (T2-T1).






















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5.1.3.  Sample

   Initial convergence time of information flooding in multi-area
   networks


   . . . . . . . . . . . . . . . .
   . +-----+  +-----+  +-----+   .
   . |NODE1|--|NODE2|--|NODE3|   .
   . +-----+  +-----+  +-----+   .
   .    |    /            |      .
   . +-----+/    +-----+  |      .
   . |NODE4|-----|NODE5|  |      .
   . +-----+     +-----+  |      .
   .                      |      .
   . Area1                |      .
   . . . . . . . . . . .+-----+. .
                        |NODE6|
                        +-----+
                           |
                        +-----+
                        |NODE7|
   . . . . . . . . . . .+-----+. .
   .                       |     .
   . +-----+            +-----+  .
   . |NODE8|------------|NODE9|  .
   . +-----+            +-----+  .
   .                       |     .
   .Area2               +------+ .
   .     ---------------|NODE10| .
   .     |              +------+ .
   . +------+. . . . . . . . . . .
     |NODE11|
     +------+
        |
     +------+
     |NODE12|
   . +------+. . . . . . . . . . .
   .    |                        .
   . +------+     +------+       .
   . |NODE14|-----|NODE15|       .
   . +------+     +------+       .
   .        \       |            .
   .         +------+            .
   .         |NODE13|   Area3    .
   .         +------+            .
   . . . . . . . . . . . . . . . .




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   Control nodes are represented by vertices and physical links are
   represented by dashed lines.  Border nodes NODE6, NODE7, NODE11 and
   NODE12 connect Area1, Area2 and Area3.

   When all these nodes enable OSPF-TE and their interfaces first become
   operational, Hello packets are flooded in the multi-area network to
   establish neighbor relationships.

   For the three areas in the network as depicted in Figure 3, all these
   nodes are switched on more or less simultaneously, so store the same
   time structure in every node is necessary to record the first sending
   moment of Hello packets.  The earliest sending moment is the starting
   point of the convergence time.

   After the establishment of neighbor relationships, DD packets are
   sent and received to compare the nodes database so as to establish
   adjacency relationships.  And the receiving moments of DD packets
   should be stored in another time structure in every node.  Then
   choose the latest moment among all receiving moments relating to DD
   packets as the end point of the convergence time of information
   flooding in this scenario.

   So the initial convergence time of information flooding in the multi-
   area network can be computed by subtracting the starting point from
   the end point.

5.2.  Convergence time of information flooding with LSPs

5.2.1.  Definition

   Convergence time of information flooding with LSPs in multi-area
   networks comprises two parts: intra-area convergence time of
   information flooding and inter-area convergence time of information
   flooding.  While intra-area convergence time of information flooding
   is further divided into several single area convergence time of
   information flooding according to the areas the cross-area-LSP
   traversed through.  And inter-area convergence time of information
   flooding refers to a time period during which the area border nodes
   synchronize their information according to RFC1583.

   Every single area convergence time of information flooding can refer
   to section 4.2.  Note that for source area the convergence time
   starts at the moment when the LSP ingress node updates its
   information.  Otherwise, for intermediate areas, as well as
   destination area, the convergence time starts at the moment when the
   ingress node of that area updates its information with respect to the
   LSP.  All the convergence time end with the last node!_s receipt of
   the updating information.



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   Setting the convergence time of information flooding with LSPs as
   undefined means the ingress node fails to receive the corresponding
   ResvConf message, which may indicate resource reservation failures or
   nodes breaking down along the cross-area LSP.

5.2.2.  Methodology

   The procedure of convergence time of information flooding in multi-
   area network, as mentioned above, comprises two parts: intra-area
   convergence time of information flooding and inter-area convergence
   time of information flooding.  Methodology for convergence time of
   information flooding in single area has been specified in Section
   4.2.2; and the methodology for inter-area convergence time of
   information flooding proceeds as follows,

   o  All control nodes in all areas enable OSPF-TE;

   o  Initial information synchronization is complete, which means all
      nodes!_ LSDB are up-to-date;

   o  Select an ingress node ID0 and an egress node ID1 in a different
      area, and create a cross-area LSP from ID0 to ID1;

   o  Wait until ID0 receives all the corresponding ResvConf messages
      that confirm the completion of resource reservation, ID0 updates
      its LSDB and forms a LSU packet LSU0.  Store a timestamp (T1) at
      ID0 as soon as the LSU packet is sent;

   o  Then the source area border node receives the LSU packet and
      summarizes the source area information into an advertisement.
      Then the border node distributes the advertisement to backbone
      area.  Store a timestamp (T2) at the border node as soon as the
      advertisement is distributed;

   o  Another timestamp (T3) should be stored locally as soon as the
      border node in destination area receives an advertisement from
      backbone area;

   o  Inter-area convergence time of information flooding can be
      computed by subtracting two timestamps (T3-T2);

   o  The convergence time of information flooding of the network can
      also be computed by subtracting two timestamps (T3-T1);

   o  If ID0 fails to receive the corresponding ResvConf message in a
      reasonable period of time, the inter-area convergence time of
      information flooding is set to undefined.




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5.2.3.  Sample

   Convergence time of information flooding with LSPs in multi-area
   networks


   . . . . . . . . . . . . . . . .
   . +-----+  +-----+  +-----+   .
   . |NODE1|--|NODE2|==|NODE3|   .
   . +-----+  +-----+  +-----+   .
   .    |    /            ||     .
   . +-----+/    +-----+  ||     .
   . |NODE4|-----|NODE5|  ||     .
   . +-----+     +-----+  ||     .
   .                      ||     .
   . Area1                ||     .
   . . . . . . . . . . .+-----+. .
                        |NODE6|
                        +-----+
                          ||
                        +-----+
                        |NODE7|
   . . . . . . . . . . .+-----+. .
   .                      ||     .
   . +-----+            +-----+  .
   . |NODE8|------------|NODE9|  .
   . +-----+            +-----+  .
   .                      ||     .
   .Area2               +------+ .
   .     ===============|NODE10| .
   .    ||              +------+ .
   . +------+. . . . . . . . . . .
     |NODE11|
     +------+
        ||
     +------+
     |NODE12|
   . +------+. . . . . . . . . . .
   .    ||                       .
   . +------+     +------+       .
   . |NODE14|=====|NODE15|       .
   . +------+     +------+       .
   .        \       |            .
   .         +------+            .
   .         |NODE13|   Area3    .
   .         +------+            .
   . . . . . . . . . . . . . . . .




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   Control nodes are represented by vertices and physical links are
   represented by dashed lines and LSPs are represented by equal signs.
   Border nodes are NODE6, NODE7, NODE11 and NODE12 which connect Area1,
   Area2 and Area3, as shown in Figure 4.

   The cross-area LSP is NODE2->NODE3->NODE6->NODE7->NODE9->NODE10->NODE
   11->NODE12->NODE14->NODE15.  When ResvConf message is received from
   every node along this LSP, meaning the resource reservation is
   complete, LSAs flooding begins from the source area, Area1.

   NODE2 sends out a LSU packet LSU1 which contains link states changes
   in Area1, and LSU1 is then flooded in Area1.  When Area1's border
   node NODE6 receives LSU1, it not only updates its own database but
   also forms an inter-area LSU packet LSU12 summarizing Area1's states
   changes and sends it to Area2's border node NODE7.  As ingress node
   of partial LSP in Area2, NODE7 also sends out a LSU packet LSU2 which
   includes link states changes in Area2 and then LSU2 is flooded in
   Area2.  Similarly, NODE11 forms an inter-area LSU packet LSU 23 and
   sends it to NODE12.  NODE12, as ingress node of partial LSP in Area3,
   forms LSU3 which is then flooded in Area3.

   LSU1, LSU2 and LSU3 are intra-area LSU packets while LSU12, LSU23 are
   inter-area LSU packets.

   Time structures are stored in every node along the sending and
   receiving of LSU packets.  Moments related to different LSU packets
   are recorded in different time structures.

   Intra-area convergence time of information flooding in Area1 can be
   computed by subtracting the end point, which can be obtain by
   choosing the latest receiving moment in Area1, from NODE2s sending
   moment.  Similarly, the starting point and end point of the intra-
   area convergence time of information flooding in Area2 are NODE7s
   LSU2 sending moment and the latest receiving moment among NODE8,
   NODE9, NODE10 and NODE11.  For Area3 the starting point and end point
   are NODE11s LSU3 sending moment and the latest receiving moment among
   NODE12, NODE13, NODE14 and NODE15.

   Inter-area convergence time of information flooding reflects the time
   required to synchronize information among border nodes: NODE6, NODE7,
   NODE11 and NODE12.  So the starting point is NODE6s LSU12 sending
   moment while the endpoint is the latest inter-area LSU packets
   receiving moment.  By subtracting the two moments, inter-area
   convergence time of information flooding for Area1, Area2 and Area3
   is computed.  Note that in Figure 4, there is only one entrance
   border node and one exit border node between two areas.  As for
   Area1, NODE6 is the only exit node, so the starting point of inter-
   area convergence time of information flooding is the moment when



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   NODE6 sends LSU12.  In the topology where there are more than one
   exit nodes in the source area, the starting moment will be the
   earliest LSU12 sending moments among the exit border nodes.

   The convergence time of information flooding in the network can be
   computed by subtracting the following two moments, one is the NODE2s
   sending moment in Area1, the other is the latest LSU23 receiving
   moment.


6.  Discussion

   The following issues are likely to come up in practice.

   o  The accuracy of convergence time of information flooding depends
      largely on the clock resolution in every node, where time
      structures are stored; so synchronization among all nodes in the
      network is crucial.

   o  Whether a convergence time of information flooding is a real
      number or undefined largely depends on the choosing of the
      reasonable waiting time before the ResvConf is received.  However,
      choosing the waiting time is complicated.  If the time is set too
      short, there will be too much "undefined" convergence time and the
      result does not reflect the network performance properly.
      However, if the time is set too long, time is wasted waiting when
      there are resource reservation failures or breaking down nodes.
      Choose the appropriate waiting time is also depending on the
      network status, if the network is light loaded, the waiting time
      can be set shorter than it is set when the network is heavy
      loaded.


7.  Security Considerations


8.  Acknowledgement

   We wish to thank Shengwei Meng, and Koubo Wu in the Key Laboratory of
   Information Photonics and Optical Communications (BUPT), Ministry of
   Education, for their valuable comments.  We also wish to thank the
   support from National 863 program.


9.  Normative References

   [RFC1583]  Moy, J., "OSPF Version 2", March 1994.




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   [RFC2119]  Bradner, S., "Key words for use in RFC's to Indicate
              Requirement Levels", RFC 2119, March 1997.

   [RFC2205]  Braden, R., Zhang, L., Berson, S., Herzog, S., and S.
              Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
              Functional Specification", RFC 2205, September 1997.

   [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
              (TE) Extensions to OSPF Version 2", September 2003.

   [RFC3945]  Mannie, E., "Generalized Multi-Protocol Label Switching
              (GMPLS) Architecture", October 2004.

   [RFC4601]  Manral, V., White, R., and A. Shaikh, "Benchmarking Basic
              OSPF Single Router Control Plane Convergence", April 2005.

   [RFC5151]  Farrel, A., Ayyangar, A., and JP. Vasseur, "Inter-Domain
              MPLS and GMPLS Traffic Engineering -- Resource Reservation
              Protocol-Traffic Engineering (RSVP-TE) Extensions",
              February 2008.

   [RFC5152]  Vasseur, JP., Ayyangar, A., and R. Zhang, "A Per-Domain
              Path Computation Method for Establishing Inter-Domain
              Traffic Engineering (TE) Label Switched Paths (LSPs)",
              February 2008.


Appendix A.  author

   Jie Zhang

   Beijing University of Post and Telecommunication

   No.10,Xitucheng Road,Haidian District

   Beijing 100876

   China

   Phone: +8613911060930

   Email: lgr24@bupt.edu.cn









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Authors' Addresses

   Min Zhang
   Beijing University of Post and Telecommunication
   No.10,Xitucheng Road,Haidian District
   Beijing  100876
   P.R.China

   Phone: +8613910621756
   Email: mzhang@bupt.edu.cn


   Hui Ding
   Beijing University of Post and Telecommunication
   No.10,Xitucheng Road,Haidian District
   Beijing  100876
   P.R.China

   Phone: +8613426082796
   Email: dinghui.ei@gmail.com


   Yongli Zhao
   Beijing University of Post and Telecommunication
   No.10,Xitucheng Road,Haidian District
   Beijing  100876
   P.R.China

   Phone: +8613811761857
   Email: yufengx386@gmail.com


   Haiyi Zhang
   China Academy of Telecommunication Research, MIIT, China.
   No.52 Hua Yuan Bei Lu,Haidian District
   Beijing  100083
   P.R.China

   Phone: +861062300100
   Email: zhanghaiyi@mail.ritt.com.cn











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   Yunbin Xu
   China Academy of Telecommunication Research, MIIT, China.
   No.52 Hua Yuan Bei Lu,Haidian District
   Beijing  100083
   P.R.China

   Phone: +8613681485428
   Email: xuyunbin@mail.ritt.com.cn











































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