Transcript Dynamic Placement of Multi-Segment Pseudowire draft-balus-bocci-martini-dyn-ms-pwe3 Editors: Luca Martini

Dynamic Placement of Multi-Segment Pseudowire
draft-balus-bocci-martini-dyn-ms-pwe3
Editors:
Luca Martini [email protected]
Matthew Bocci [email protected]
Florin Balus [email protected]
PG 1
Background
> Basic PW setup and maintenance - draft-ietf-pwe3-control-protocol
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Covers SS-PWs
> PW Switching - draft-ietf-pwe3-segmented-pw
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Statically configured MS-PWs
> Two original proposals for LDP based MS-PWs:
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draft-shah-bocci-pwe3-ms-pw-signaling-01.txt
draft-balus-mh-pw-control-protocol-02.txt
Drafts merged following Paris IETF
> Dynamic Placement of MS-PW - draft-balus-bocci-martini-dyn-ms-pwe3-00.txt
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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
PG 2
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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 <addressing> format carried in AII Type 2
PG 3
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Addressing Format
Metro-Access Interconnection Use Case A
S-PE
Metro A1
T-PEs
S-PE
WAN
Core
Metro A2
S-PE
Provider A
Globally unique addressing for PW
endpoints that allows also:
T-PEs
Inter-Provider
Use Case
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
PG 4
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MS-PW Information Model – Unique Identification
of PW Endpoint
LSPa12 = (AGI, TAII2, SAII1)
MS-PWa
LSPa21 = (AGI, TAII1, SAII2)
SS-PW
SS-PW
T-PE 1
S-PE
VFx
SP
LDP
T-PE 2
VFy
LDP
Unique Endpoint ID
• AII11 = Global ID-Prefix1-AC ID11
Unique Endpoint ID
• AII21 = Global ID-Prefix2-AC ID21
Consistent information model with SS-PWs
PG 5
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Signaling Procedures for SS and MS-PWs
MS-PWs as a superset of the SS-PWs
1’. T-PE2 (IP2) provisioned with
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AGI = 40
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SAII (AC ID) = 200
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TAII (AC ID) = 100
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Destination PE = IP1
1. T-PE1 (IP1) provisioned with
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AGI = 40
SAII (AC ID) = 100
TAII (AC ID) = 200
Destination PE = IP2
4. On LM receipt check
TAII against “routing
table”. No full match
on “local i/f”. Longest
match =>NSH
2. Check TAII against
routing table. Longest
match => next
signaling hop (NSH).
T-PE1
22.
S-PE
P
P
SP
VF
6. On LM receipt check
TAII against “routing
table”. Full match on
“local i/f” implies T-PE.
LDP1
30. T-PE2
VF
LDP2
3. SS-PWa LSP Fwd
5. SS-PWb LSP Fwd
8. SS-PWa LSP Rev
7. SS-PWb LSP Rev
PG 6
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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
PG 7
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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 1:1 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
PG 8
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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-> Segmented PWs-> Dynamic Placement of MS-PWs
PG 9
draft-balus-bocci-martini-dyn-ms-pwe3