IEEE 802.1ah First Draft
Paul Bottorff
March 14, 2005
P802.1ah - Provider Backbone Bridges –
Targeted Timeline
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IEEE 802.1ah (Provider Backbone Bridge) Context
802.1ad
Interfaces
Provider Backbone Bridge
Network (802.1ah)
Provider Bridge Network
(802.1ad)
Provider Bridge Network
(802.1ad)
Provider Bridge Network
(802.1ad)
802.1aj
CFM(802.1ag) Runs
End-to-end
MRP(802.1ak) Runs in
802.1ad & 802.1ah
4
Draft 0 Content
> Draft 0 available at: http://www.ieee802.org/1/files/private/ah-drafts/d0
> Much of P802.1ad is included within editor’s notes
> Added clauses 23, 24, and 25
• Clause 23: Support of the MAC Service by Provider Backbone Bridged
Networks
• Clause 24: Principles of Provider Backbone Bridged network operation
• Clause 25: Principles of Provider Backbone Bridge operation
> Clause 1 contains some suggestions for scope
> Clause 3/4 contains new Provider Backbone Bridge definitions
and acronyms
> Clause 9 contains I-TAG VCI format
5
Open items in Draft 0
> Clause 5: Conformance statement
> Clause 12: Management for PBB bridges
> Clause 23:
• Port based interface description
• I-Frame based interface description
> Clause 24:
• Interaction of Provider Backbone Edge Bridges with Provider Bridge
spanning trees
• Operation of Provider Backbone Bridge spanning trees
> Clause 25:
• Details of I Component and B Component operation
• Operation of address correlation data base
> Informative annex on an integrated C-VLAN aware component
6
Backup Slides
Provider Backbone Bridge Network (PBBN)
PB
PB
PBB
PBB
PB
PB
PB
PBB
PBB
• PB: Provider Bridge (as defined by 802.1ad)
• PBB: Provider Backbone Bridge Edge (as defined by 802.1ah)
8
Provider Network Example
Customer
Equipment
Provider Bridged
Network
C
CE
PB
A
PB
C
CE
P
P
PB
PB
CE
Provider Backbone
Bridged Network
A
PB
C
D
B
B
B
PB
B
PBB
CE
Customer
Equipment
PB
Provider
Bridge
PBB
P
C
PEB
Customer
LAN
A
Access
LAN
CE
Legend:
9
C
PBB
Provider
Backbone
Bridge
A
PB
P
Provider
LAN
PEB
Provider
Edge
Bridge
D
Boundary
LAN
B
Backbone
LAN
Provider Network Port
Customer Network Port
D
B
PB
B
P
P
PBB
B
B
P
PB
PBB
P
P
A
D
D
PBBN Provides Multi-Point tunnels between PBNs
PBN
PBN
B-VLANX
PBB
S-VLAN4
BBN
PBB
PBB
PBB
S-VLAN3
PBN
PBB
PBB
PBN
S-VLAN1
S-VLAN2
B-VLANY
• BB PB: Provider Backbone Bridge Edge
• Each B-VLAN carries many S-VLANs
• S-VLANs may be carried on a subset of a B-VLAN (i.e. all P-P S-VLANs could be
carried on a single MP B-VLAN providing connection to all end points.
10
Agreed Terminology
> IEEE 802.1ad Terminology
•
•
•
•
•
•
C-TAG
C-VLAN
C-VID
S-TAG
S-VLAN
S-VID
Customer VLAN TAG
Customer VLAN
Customer VLAN ID
Service VLAN TAG
Service VLAN
Service VLAN ID
> Additional Provider Backbone Bridge Terminology
•
•
•
•
•
•
•
11
I-TAG
I-SID
C-MAC
B-MAC
B-VLAN
B-TAG
B-VID
Extended Service TAG
Extended Service ID
Customer MAC Address
Backbone MAC Address
Backbone VLAN (tunnel)
Backbone TAG Field
Backbone VLAN ID (tunnel)
Extended Service VLAN IDs In Backbone
BB
PB
S-VLAN4
S-VID41
BB
PB
I-SID4
B-VLANX
BBN
S-VLAN3
BB
PB
I-SID3
S-VID31
S-VID32
BB
PB
S-VID33
BB
PB
BB
PB
B-VLANY
S-VID42
S-VLAN1
S-VLAN2
• BB PB: Provider Backbone Bridge Edge
• An I-SID uniquely identifies a S-VLAN within the Backbone
• The MAP Shim translates between S-VID and I-SID
• The I-SID to(from) S-VID mapping is provisioned when a new
service instance is created
12
Single I-SID per S-VLAN
S-VID2
BB
PB
BBN
BB
PB
S-VID3
BB
PB
I-SID
S-VID1
BB
PB
> Regardless of the I-SID address size the map tables
only have 4096 entries since only one I-SID exists per
S-VLAN and only 4096 S-VLANs exist per Provider
Bridge.
13
> A different S-VID in each PBN maps to the I-SID
Site Connectivity B-VLAN ID
B-VLANX
BB
PB
S-VLAN4
BBN
BB
PB
BB
PB
S-VLAN3
BB
PB
BB
PB
S-VLAN1
BB
PB
S-VLAN2
B-VLANY
> B-VLANs are addressed like regular VLANs with a 12 bit
B-VID
> B-VID and I-SID need to be separate ID spaces to allow
many S-VLANs to be carried in a single B-VLAN
14
Backbone POP MAC Address
BB PB
BBN
BB PB
B-MAC4
BB PB
Frame
B-MAC1
BB PB
Frame
DA <- B-MAC4
SA <- B-MAC1
Frame
15
>
B-MAC Addresses identify the Edge Provider Backbone Bridges (BB PB)
>
B-MAC Addresses are learned by other Edge Backbone Edge Bridges
>
The backbone edge MAC address determines which edge on the B-VLAN will receive the
frame.
>
Frames may be flooded by sending with broadcast or multicasts DA B-MACs to the B-VLAN.
>
Map shims filter based on the I-SID removing any misaddressed frames
MAP Shim Correlation Table
Provisioned
Provider
Addresses
0x001
0x010090
0x0c0
B-MAC Addresses
Customer
Addresses
0x002
0x070707
0x007
0x999999999999
C-MAC Addresses
0x111111111111
0x888888888888
S-VID
I-SID
B-VID
0x222222222222
0xfff
0x808080
0x0c0
C-MAC Address
0x777777777777
0xdddddddddddd
16
>
In the beginning the MAP Shim is provisioned with the correlation between
the S-VID, I-SID, and B-VID
>
During operation the MAP Shim learns both B-MAC addresses and C-MAC
addresses
>
The MAP Shim keeps track of which C-MAC addresses are behind which BMAC
>
The correlation data is used to encapsulate frames from the PBNs
Customer, PB, BB Spanning Trees
Customer Spanning Trees
QB
QB
QB
PB
PB
PB-BB
PB-BB
PB
QB
PB
PB
QB
QB
QB
PB
BB
QB
QB
PB
PB
PB Spanning
Trees
PB
PB-BB
QB
PB
BB
BB
Spanning
Trees
PB Spanning
Trees
> Customer spanning trees may extend over Provider Network
> PB Network and BB Network spanning trees must be decoupled
to scale the provider network
17
> Provider Backbone Bridge may conform to the requirements for
an Interconnect Medium
PBB Shim Functions
802.1ad
>
Relay
MIF
802.1ad
PBB
S-shim
MIF
MAC
(802.3)
•
MCF
PBB
T-shim
>
Virtual MAC
T-Shim Operations
•
•
•
Backbone Edge
18
Maps S-VID from 802.1ad into larger
Extended Service VID (I-SID)
Filters L2 control packets sourced by
core relays or by provider bridge
relays (divides spanning trees)
MAC
(802.3)
BB
MCF
S-Shim Operations
•
PB
Relay
MIF
MIF
Does encap/decap of 802.1ad frame
Learns and Correlates Backbone
POP and Customer MAC addresses
Filters L2 control packets sourced
by core relays or by provider bridge
relays (divides spanning trees)
Ethernet Service Types
MEF Ethernet Virtual Connections (EVCs)
E-LINE
Router Mesh
E-TREE
Hub & Spoke
E-LAN
Multi-Site
19
Pt-Pt, Like
Duplex Ethernet
Any-to-any
Pt-MPt, Like
EPON Ethernet,
Root-to-Leaf and
Leaf-to-Root
MPt, Like VLAN,
Any-to-any
E-LINE Dominates Today
> E-LINE is a natural leased line replacement for subscribers
•
•
•
•
Ethernet leased lines offer high bandwidth
Lines provide bandwidth on demand
Interfaces are compatible with off the shelf Ethernet switches/routers
Best for router mesh
> E-LINE provides natural migration for carriers
•
•
•
•
•
Consistent with current operations model
Allows carrier equipment reductions
Bill models can follow well understood FR services
Current QoS models allow both traffic control and service monitoring of ELINE service offerings
Service OAM models for E-LINE are relatively straightforward
> Each E-LINE service instance requires 1 S-VLAN
20
E-TREE Ideal For ISP Connect
> E-TREE Future Service With Great Promise
•
•
Useful as a multiplexed connection to an application service provider like an ISP
Service is unlike traditional Ethernet since leaf nodes can not talk with each other
> E-TREE has deployment issues
•
No clear billing model
• For instance if one leaf is disconnected is the circuit down?
• What is the distance of the tree?
•
•
21
OAM management not fully understood
QoS model non-existant, SLAs can only provide Best Effort
E-TREE S-VLAN Mapping
Pt-MPt, Like
EPON Ethernet,
Root-to-Leaf and
Leaf-to-Root
E-TREE
Hub & Spoke
Hub
Port
Spoke
Ports
> Each E-TREE service instance requires 2 S-VLANs
> Both S-VLANs comprising an E-TREE S-VLANs are unidirectional
> The S-VLANs of and E-TREE service instance are typically on the
multiplexed on the same port
22
Some Carriers Will Use E-LINE in Hub and
Spoke Arrangement
Pt-Pt
Root-to-Leaf and
Leaf-to-Root
E-LINE
Hub & Spoke
Hub
Port
Spoke
Ports
> Hub port would usually be multipexed to allow the multiple Pt-Pt
attachments.
> Each E-LINE is a seperate managed S-VLAN
> This arrangement allows use of E-LINE management, billing, and QoS
> Many more S-VLANs are required
23
E-LAN Many Future Applications
> E-LAN is deployed for broad connectivity in select network
•
•
•
•
Interconnect of multiple corporate sites
Multi-player gaming
Ubiquitous any-to-any connectivity
E-LAN has many future applications
> E-LAN has deployment issues
•
•
Deployments are very spotty
Unclear billing model
• How is availability defined?
• No definitions for QoS or performance measurement
• What is the distance of a E-LAN
•
•
Unclear management models
Unlike existing carrier service offerings
> Each E-LAN service instance is a single S-VLAN
24
Prototypical Major Metro Area
> Business Subscriber Population 100K-2M
• San Jose Yellow Pages ~100K businesses
• The SF Bay Area lists ~1M businesses
> Large Business Sites 500-5,000
> Residential Subscriber Population 1M-20M
> Leased Line Density 10K-200K
• Roughly 1/10 Yellow Page Listings
> Application Service Provider Sites 100-2000
• Large APSPs sites may service residental
25
Major MSA Networks
Typical SP
Access
Business
Small Office
Medium Office
Large Office
CLE
Network Scale
>10,ooo Remotes
>10,ooo CLEs
>500 COs
100-200 COs
10-60 COs
Metro Scale
>4,ooo Remotes
>1,ooo CLEs
>50 COs
>20 COs
>4 COs
Typical Metropolitan Serving
Area – MSA
> MSA example shown
> ASIA/PAC more CO/MSA
> Europe less
26
CO/MSA
Support 1,000,000 Service Instances
>
Must be able to support E-LINE service for leased line replacement for entire MSA
•
•
>
Must support E-LINE for APSP to Subscribers
•
•
•
•
>
200K E-LINE S-VLANs for leased line replacement
200K E-LINE S-VLANs for APSP
20K E-TREE S-VLANs
? E-LAN Service Instances
Designing Into A Corner Will Not Instill Confidence In Future
•
•
•
27
Advanced peer applications
Number of service instances speculative, however could be large
Totals
•
•
•
•
>
Not all service providers will allow E-TREE because of deployment problems
The objective of an additional 200K E-LINE is adequate for transition until E-TREE
Requirements for around 10K E-TREE instances
Requires 20K S-VLANs
Must support E-LAN for APSP and B-B
•
•
>
This is the way Ethernet is entering the markets
The objective is 200K E-LINE instances
Set Objectives to at least 1,000,000 service instances E-LINE, E-TREE, E-LAN
E-LAN service will eventually become important for coupling small groups
Allow E-TREE and E-LAN service scaling to at least 100,000 for future growth