More Related Content
Similar to The Role of PBB in Service Provider Networks
Similar to The Role of PBB in Service Provider Networks (20)
More from Scott Foster (20)
The Role of PBB in Service Provider Networks
- 1. The Role of PBB in Service Provider Networks
Nick Del Regno
Principal Member of Technical Staff
Verizon Core Network Technology
nick.delregno@verizon.com
© Verizon 2010 All Rights Reserved Page - 1
- 2. Agenda
Verizon Ethernet Networks
Provider Bridged Network Challenges
PBB in Native Ethernet Networks
VPLS Challenges
PBB in VPLS Networks
© Verizon 2010 All Rights Reserved Page - 2
- 3. Verizon Ethernet Networks
Switched Ethernet Service
– LATA-bound Ethernet Service Network
– EVPL, EP-LAN, EVP-LAN Services
– Provider Bridging & Provider Backbone Bridging
Converged Packet Architecture
– National/Global Ethernet Service Network
– EVPL, EP-LAN & EVP-LAN Services
– VPLS & VPWS based services
End-to-End Ethernet Solutions
© Verizon 2010 All Rights Reserved Page - 3
- 4. Provider Bridging Challenges
Ethertype
C-VLAN
DA SA Tag Payload FCS
VLAN ID Space Limitations
– 12-bits = 4096 VLANs
Customer VLAN Space Overlap
Global Nature of VLANs
– Switch
– Network
Historical lack of VLAN translation capability
© Verizon 2010 All Rights Reserved Page - 4
- 5. Early Solutions
Ethertype
S-VLAN C-VLAN
DA SA Tag Tag Payload FCS
VLAN Stacking
– Q-in-Q
– 802.1ad
S-VLAN expands addressable VLAN space
– 16,777,216 VLANs (4096 C-Tags x 4096 S-Tags)
– Doesn’t help MAC Scaling
S-VLAN often represents customer EVC
– 4096 EVCs per network
– Too few for large SP networks
© Verizon 2010 All Rights Reserved Page - 5
- 6. Topological Considerations
(Possible)
MAC Choke
Points
Early deployments
– Flat Topologies
– Tree & Branch Architectures
Hierarchy Introduced to Scale
– Improves MST convergence
– Creates MAC scaling challenges
– VLAN Scaling still limited
© Verizon 2010 All Rights Reserved Page - 6
- 7. Provider Backbone Bridging (802.1ah)
Ethertype
C-VLAN
B-DA B-SA B-Tag I-Tag C-DA C-SA Tag Payload FCS B-FCS
MAC + Tag Stack
– Backbone MACs pre-pended to packet
– B-Tag is a VLAN Tag (EtherType: 0x88A8)
– New I-Tag
• EtherType: 0x88E7
• Priority, Drop Eligibility and “Use Customer Addresses” Flags
• 24-bit Service Instance ID = 16,777,216 IDs
Introduces Backbone Tunnel Concept
– Multipoint B-VIDs for ELAN traffic
– Point-to-Point B-VIDs for ELINE traffic
Hides customer MACs
– C-MACs visible within PB switches and Backbone Edge Bridges
(BEBs)
© Verizon 2010 All Rights Reserved Page - 7
- 8. PBB in Provider Bridged Networks
No Customer MAC Visibility
BCB BCB
I-B Tagged Packets
IB-BEB /
IB-BEB IB-BEB IB-BEB
BCB
S-Tagged Packets
Legacy Legacy Legacy Legacy Legacy Legacy Legacy Next Gen
Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet
Switch Switch Switch Switch Switch Switch Switch Switch
Customer Edge
C-Tagged Packets
BCB: Backbone Core Bridge
IB-BEB: Backbone Edge Bridge
© Verizon 2010 All Rights Reserved Page - 8
- 9. PBB in Provider Bridged Networks
Improved Scaling
– No Customer MAC Visibility in Network Core
– 16 Million Service IDs
– Scalable Layer 2 Solution
• MPLS/VPLS not required
Works well with Multiple Registration Protocol
– MMRP for MAC Registration
– MVRP for VLAN Registration
MSTP for Topology Management
G.8031 for P2P Tunnels
– 50mS resiliency for EVPL Traffic
Well suited for Multicast/Broadcast vs. VPLS
Simpler Evolution from PB networks vs. MPLS
© Verizon 2010 All Rights Reserved Page - 9
- 10. VPLS Challenges
PE PE
PE PE
P P
PE PE
PE PE
Requires Full Mesh of LSPs
– LDP or RSVP-TE
– 150 PEs results in over 22,000 LSPs
• Not to mention Fast Reroute (FRR) Bypass/Detour LSPs
Results in Full Mesh (or more) of Pseudowires
Large networks result in LSP exhaust
– Especially at Transit Locations
• US <-> EMEA
• US <-> APAC
© Verizon 2010 All Rights Reserved Page - 10
- 11. H-VPLS Scaling Solutions
PE PE
MTU
PE PE
MTU MTU
PE PE
MTU
PE PE
All Customer
MACs visible at
MTUs
Dramatically Reduces Number of LSPs
– Full Mesh Required between “MTUs”
Reduces number of Pseudowires
– PWs needed only between PE & MTU and between MTUs
Creates MAC Address Choke Points
– ALL Customer MACs visible at MTU
– Can approach MAC scale limits of hierarchical boundary equipment
© Verizon 2010 All Rights Reserved Page - 11
- 12. PBB + HVPLS
PE + PE +
PE
IB-BEB PE
IB-BEB
MTU
PE + PE +
PE
IB-BEB PE
IB-BEB
MTU MTU
PE + PE +
PE
IB-BEB PE
IB-BEB
MTU
No Customer PE + PE +
IB-BEB PE
IB-BEB
MAC visibility in
VPLS core
Leverage HVPLS to reduce LSP & PW scale
Leverage PBB to reduce Customer MAC Scale
PBB in the PE
– Encapsulate customer traffic in PBB
– MTU Devices only bridge on Backbone MAC Address
• Similar to BCB function in Native Ethernet backbones
© Verizon 2010 All Rights Reserved Page - 12
- 13. PBB vs MPLS?
No such thing
Agnostic tool
– Helps scale native Ethernet networks
– Helps scale VPLS networks
PBB-TE vs MPLS-TP = TBD
© Verizon 2010 All Rights Reserved Page - 13
- 14. Questions?
© Verizon 2010 All Rights Reserved Page - 14