Outline
Ethernet services driving metro/edge innovation
Overview of transport encapsulation technologies
MPLS-based
Ethernet-based Side-by-side comparison Summary
…and a prediction
Ethernet services driving metro/edge innovation (1)
Ethernet-based L2VPNs are on the rise
Many analysts forecast global Ethernet-based services revenue to double in two years
MEF-defined Carrier Ethernet
services

E-Line using P2P EVCs

E-LAN using MP2MP EVCs

E-Tree using Rooted MP EVCs
Embraced by large and small carriers and operators
Requirements appearing in
virtually every new tender
Ethernet services driving metro/edge innovation (2)
Evidenced by rapid pace of protocol development

MPLS-based transport:

MPLS VPLS

MPLS H-VPLS

Transport-MPLS

Ethernet-based transport:

IEEE 802.1ad Provider Bridging

IEEE 802.1ah Provider Backbone Bridging

Provider Backbone Transport
May be standardized as PBB-TE
MPLS
T-DA  
T-SA  
T-Tag  
Tunnel  
VC  
C-DA  
C-SA  
88-a8  
S-Tag  
81-00  
C-Tag  
Data  
FCS  
PBB/PBT Backbone-DA Backbone-SA
PB
Customer-DA Customer-SA S-Tag EType S-VID, PCP, DE C-Tag EType C-VID, PCP Backbone-Tag Instance-Tag Customer-DA Customer-SA S-Tag EType S-VID, PCP, DE C-Tag EType C-VID, PCP
C-DA  
C-SA  
88-a8  
S-Tag  
81-00  
C-Tag Data FCS  
B-DA  
B-SA  
B-Tag  
I-Tag  
C-DA  
C-SA  
88-a8  
S-Tag  
81-00  
C-Tag  
Data  
FCS  
Carrier Ethernet services transport landscape
Carrier Ethernet services transport: VPLS
Tunnels tied to physical infrastructure
Dedicated P2P pseudowire mesh with split-horizon forwarding within the core between PEs for every service instance
Scalability

PW sessions signaled via MPLS control plane

Tunnels scale as PEs are added

At a minimum for n PEs there are n tunnels (20 bits)

Pseudowires scale n!/2(n-2)! * service count (20 bits)
Carrier Ethernet services transport: H-VPLS
Introduced to offload pseudowire mesh scaling issues as service count grows
MTU-s introduction requires
fewer PEs and smaller PW mesh
Implementations often seek to increase service count, which in turn drives larger MAC table size requirements
Scalability

PW sessions signaled via MPLS control plane

Hub and spoke PW architecture reduces PW mesh issue

As service count grows, trade off MAC table size vsPW mesh
Carrier Ethernet services transport: T-MPLS
ITU-T defining T-MPLS (subset of MPLS useful for P2P transport) Retains MPLS encap or possibly uses Dry Martini (no VC label)
Resiliency

Signaling connectivity separated from resiliency mechanisms

Transport OAM Y.1711 / Y.1731 being leveraged
Scalability

PW sessions signaled via GMPLS control plane

1M services (20 bit)

Anticipated to interwork with traditional MPLS core PE/P devices
Carrier Ethernet services transport: PB
Known as Q-in-Q

IEEE 802.1ad Provider Bridging Most common customer interface 4K Services (12-bits) Unique Service ID per Service

(i.e., S-VID) Forwarding is basic L2 with flooding/learning based on MAC
DA/SA at the S-VID level and
xSTP for loop prevention
Scalability
Limited to 4K
Carrier Ethernet services transport: PBB
4K Interconnect Flood Domains Unique Service ID per Service
(i.e., LAN = I-SID) Forwarding is basic L2 with flooding/learning based on MAC DA/SA at the B-VID level and xSTP for loop prevention Service activation is simpler since I-SID association is comparable to S-VID
configuration Scalability

Massive service scale (24-bit)

No need to burn an I-SID at every node for every service to build a P2P mesh

C-MACs learned and associated per B-VID/I-SID
TRUE CARRIER ETHERNET™
Carrier Ethernet services transport: PBT
Provides P2P service connectivity Tunnels interconnect Ethernet access clouds Resiliency
Primary and backup tunnels
monitored by IEEE 802.1ag CFM Unique Service ID per Service
(i.e., I-SID)
Scalability

Tunnel scale (58-bit space)

Service scale (24-bit space)

I-SID per P2P service
Carrier Ethernet services transport: PBT-LAN
Tunnels are now logical in the core with a full mesh
Unique Service ID per Service
(i.e., I-SID)
Split Horizon forwarding at the tunnel level per I-SID
Resiliency
Primary and backup tunnels
monitored by IEEE 802.1ag CFM
Scalability
4K tunnels could easily be signaled via RSVP-TE, GMPLS, etc
Carrier Ethernet services transport: side-by-side
Ethernet Services Tunnel Scale
(N=PE nodes) Pseudowire Scale
Service Scale
Protection
Dual Homing
Control Plane
Split Horizon Forwarding
OAM
VPLS H-VPLS
P2P, LAN P2P, LAN
N up to N up to
N! / 2*(N-2)! N! / 2*(N-2)!
N! / 2(N-2)! * N! / 2(N-2)! *
Services Services
100s 1000s
FRR FRR
Yes
OSPF/IS-IS w/ RSVP-TE and LDP
Yes
Virtual Ping
Virtual Traceroute
BFD
T-MPLS
P2P
Service count
Service count 1M Y.1720 Y.mrps
GMPLS
No
PBB PBT PBT-LAN
P2P, LAN P2P P2P, LAN 4K Flood 2 * Service
N! / 2*(N-2)!
Domains Count
N/A
16M
In-Tunnel In-Tunnel
xSTP
CCM CCM No Yes Yes xSTP only for Future Future Loop OSPF/IS-IS w/ OSPF/IS-IS w/ Prevention RSVP-TE RSVP-TE
No Yes
Virtual Ping
Virtual Traceroute
CFM
Summary Carrier Ethernet services growing quickly
Enabled by interoperable international standards
Driven by cost-effective, innovative implementations Multiple competing technologies exist to transport Carrier
Ethernet services in metro edge ↔ customer edge
aggregation networks
Ultimately, carriers will determine what will be predominant technology
However, equipment vendors will indirectly determine the outcome…
Since Ethernet and MPLS-based transport techniques have naturally evolved the cost-effective, highest performing, easiest to manage and scale technologies will win
Thank you