Dynamic%20Placement%20of%20Multi-Segment%20Pseudowire%20draft-balus-bocci-martini-dyn-ms-pwe3

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Dynamic Placement of Multi-Segment
Pseudowiredraft-balus-bocci-martini-dyn-ms-pwe3
Editors Luca Martini lmartini_at_cisco.com Matthew
Bocci Matthew.Bocci_at_alcatel.co.uk Florin Balus
balus_at_nortel.com
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Background

• Basic PW setup and maintenance -
  draft-ietf-pwe3-control-protocol
• Covers SS-PWs
• PW Switching - draft-ietf-pwe3-segmented-pw
• Statically configured MS-PWs
• Two original proposals for LDP based MS-PWs
• draft-shah-bocci-pwe3-ms-pw-signaling-01.txt
• draft-balus-mh-pw-control-protocol-02.txt
• Dynamic Placement of MS-PW - draft-balus-bocci-mar
  tini-dyn-ms-pwe3-00.txt
• Extensions to PW switching to allow dynamic
  selection / configuration of the S-PEs
• Main focus on using FEC 129 to enable signaled
  end to end PW
• Compatible with both SS and MS PWs

Drafts merged following Paris IETF
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MS PW Requirements Addressed

• Dynamic End-to-end Signaling
• Automatic determination of intermediate S-PEs
• Minimal number of provisioning touches, i.e. only
  at the T-PEs
• Same set of T-PEs/S-PEs for both directions of a
  MS-PW
• Allow correct OAM behavior
• Signaling of traffic parameters to allow
  admission control / next hop selection at T/S-PEs
• PW Redundancy
• Explicitly specify a set of S-PEs for a MS-PW
• End-to-end negotiation of OAM Capability

• Requirements addressed with minimal changes to
  existing PW Signaling
• Re-using existing FEC - new ltaddressinggt format
  carried in AII Type 2

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Addressing Format
Metro-Access Interconnection Use Case A
S-PE
S-PE
Metro A1
WAN Core
Metro A2
S-PE
T-PEs
T-PEs
Provider A
Inter-Provider Use Case

• Globally unique addressing for PW endpoints that
  allows also

S-PE

• New Format Required
• Summarization
• SP to administer their own prefixes
• OAM, Privacy

Provider B
T-PE

• Use of FEC129, AII Type 2 see
  draft-metz-aii-aggregate-01.txt
• Enables a unique PW end point identifier to
  avoid configuration at each hop

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MS-PW Information Model Unique Identification
of PW Endpoint
SS-PW
SS-PW
S-PE
T-PE 1
T-PE 2
SP
VFx
VFy
LDP
LDP
Consistent information model with SS-PWs
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Signaling Procedures for SS and MS-PWsMS-PWs as
a superset of the SS-PWs
2. Check TAII against routing table. Longest
match gt next signaling hop (NSH).
6. On LM receipt check TAII against routing
table. Full match on local i/f implies T-PE.
S-PE
T-PE2
T-PE1
P
P
SP
VF
VF
LDP1
LDP2
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Disseminating the routing information

• Static Provisioning - Default Gateway/Summarized
  L2 Address
• Dynamic Advertisement e.g. BGP-MP
• Address Aggregation possible
• e.g. provision/advertise only the Global ID part
• As new potential T-PEs are introduced in the
  network, their Layer 2 address(es) is
  provisioned/advertised

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Other Related Procedures

• QoS TLV may be included in the Signaling Message
• New, TSPEC-based format for Quantity Of Service
• CAC Executed Against the Tunnel to Originator of
  the Local LDP Session
• Explicit Routing
• Use existing ER TLV format
• Enables also PW 11 Protection, diverse paths
• OAM Negotiation
• Re-uses procedures described in
  draft-ietf-pwe3-segmented-pw-01.txt
• New format (Global ID-Prefix) introduced for PW
  Switching TLV to allow for tracing MS-PW path
• FEC128 Support
• Interconnect Single Hop, FEC128-based domains via
  FEC129 Network
• TAII, SAII like information carried for FEC128
  inside Interface Parameters

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Next Steps

• We think we have a good start
• Need feedback on the hybrid FEC128, FEC129 usage
  case
• Make it WG document
• High level of interest, many contributors
• Logical progression, adds to the existing
  procedures
• PW Control-gt Segmented PWs-gt Dynamic Placement of
  MS-PWs