1. IEEE 802.1Qca Path Control and Reservation
Joint IEEE-SA and ITU Workshop on Ethernet
IEEE 802.1Qca Path Control and Reservation
János Farkas,
Ericsson
Geneva, Switzerland, 13 July 2013

2. Path Control and Reservation (PCR)
Outline
Background
Shortest Path Bridging (SPB) [IEEE 802.1aq, IETF RFC 6329]
Path Control and Reservation (PCR)
P802.1Qca project goals
Explicit Path (EP) establishment
Support for reservation and redundancy
Geneva, Switzerland,13 July 2013

3. Background – Shortest Path Forwarding
BR A
BR A
BR C
BR B
BR D
BR E
BR A
BR E
BR B
BR E
BR B
BR D
BR C
BR D
BR C
SPB Shortest Path Bridging
RSTP Rapid Spanning Tree Protocol
RSTP Rapid Spanning Tree Protocol
MSTP
Multiple Spanning Tree Protocol
MSTP
Multiple Spanning Tree Protocol
Shortest Path Bridging (SPB): each bridge has its own Shortest Path Tree (SPT)
Frame forwarding is on the shortest path
Geneva, Switzerland,13 July 2013

4. Background – Shortest Path Bridging
IEEE 802.1aq SPB is an add-on to IS-IS
Single link state control for large networks
Scalability
High degree of automation
Deterministic multi-path routing for unicast and multicast
Fast convergence
All standards supported, e.g. CFM
MEF services natively provided
E-LINE, E-TREE, E-LAN
Geneva, Switzerland,13 July 2013

5. IEEE P802.1Qca Path Control and Reservation (PCR)
Extend IS-IS for bridges beyond shortest path capabilities
Explicit paths
Bandwidth and stream reservation
Redundancy for data flows (protection, restoration)
Distribution of control parameters for time synchronization and scheduling
Geneva, Switzerland,13 July 2013

6. Explicit Paths
Explicit Paths(EP) are determined by Path Computation Element(s) (PCE)
Point-to-point
Multipoint (point-to-multipoint or multipoint-to-multipoint
IS-IS installs the explicit paths
Single PCE
e.g. data center network; PCE: application on a VM
Multiple PCEs
e.g. time-sensitive network; PCE: application on bridges
PCE
VM: Virtual Machine
Ctrl PDUs
IS-IS
PCE
PCE
IS-IS
Path 1
Path 1
EB 1
EB 4
EB 4
EB 1
CB 5
Server
Path 2
Host 2
Host 1
EB 3
Path 2
EB 2
EB 3
Path 3
EB 2
Host 4
Host 3
Geneva, Switzerland,13 July 2013

7. IS-IS Support for Reservation and Redundancy
IS-IS support for Stream Reservation Protocol (SRP)
PCE + IS-IS  Explicit Path
SRP  Reservation along EP
Basic reservation by IS-IS (1 PCE)
Redundancy
Maximum disjoint paths for protection
PCE + IS-IS  Explicit Paths
Protection mechanism on top of the EPs
Loop Free Alternates (LFA): reroute in a few ms
IS-IS
PCE
Request
Topology etc.
Path(s)
Geneva, Switzerland,13 July 2013

8. Thank You!
Geneva, Switzerland,13 July 2013