Download R-APS Virtual Channel

Joint ITU-T/IEEE Workshop
on The Future of Ethernet Transport
(Geneva, 28 May 2010)
G.8032 : Ethernet Ring protection
characteristics, architectures
and the Ring APS protocol
Satoshi NARIKAWA
NTT
(G.8032 Acting Co-editor)
Geneva, 28 May 2010
Outline
Objectives and Principles
Basic protection mechanism
Revision notes
Detailed functionality
Future work
Summary
Geneva, 28 May 2010
2
Outline
Objectives and Principles
Basic protection mechanism
Revision notes
Detailed functionality
Future work
Summary
Geneva, 28 May 2010
3
Objectives and Principles
Protection switching on Ethernet layer
Use of Ethernet OAM frames called R-APS
message for protection behavior
Preventing any loops by blocking mechanism
VLAN based protection switching
Sub-50msec protection switching
Support of administrative commands
A
B
F
C
E
Geneva, 28 May 2010
A
D
B
F
A
C
E
D
B
F
C
E
D
4
Outline
Objectives and Principles
Basic protection mechanism
Revision notes
Detailed functionality
Future work
Summary
Geneva, 28 May 2010
5
Basic
protection mechanism
R-APS(SF)
A
B
F
A
C
E
D
B
F
A
C
E
D
B
F
C
E
D
R-APS(SF)
Normal condition
Block RPL (Ring Protection Link)
Failure condition
Block failed link
Send R-APS messages
Unblock RPL
Perform FDB flush on all ring node as needed
Geneva, 28 May 2010
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Outline
Objectives and Principles
Basic protection mechanism
Revision notes
Detailed functionality
Future work
Summary
Geneva, 28 May 2010
7
G.8032 (06/2008)
Revision approved in June 2008
Supported Features
Single ring protection
Revertive behavior
State based flush logic
Ring
Geneva, 28 May 2010
8
G.8032 (04/2009)
Amendment approved in April 2009
Supported Features
Multi-ring protection with R-APS Virtual Channel
Revertive behavior
State based flush logic
Flush propagation
Major
Major
Sub
Geneva, 28 May 2010
Major
Sub
Sub
9
G.8032 (03/2010)
Revision approved in March 2010
Supported Features
Multi-ring protection with/without R-APS Virtual Channel
Revertive/non-revertive behavior
Flush logic with Node-ID and BPR (Blocked Port
Reference) mechanism
Administrative commands (Manual/Forced switch, Clear)
Ability to block RPL at both ends of link
Multiple (logical) ERP Instances over a given physical ring
Major
Major
Major
Major
Sub
Sub
Geneva, 28 May 2010
Sub
Sub
Sub
10
Outline
Objectives and Principles
Basic protection mechanism
Revision notes
Detailed functionality
Future work
Summary
Geneva, 28 May 2010
11
Interconnected Rings
G.8032 supports for a
network of interconnected
rings based on the following
terminology.
Major
Major
Sub
Sub
Interconnection Node
connects between Ethernet
rings
Major
Major Ring
constitutes a closed ring
is controlled by its own ERP
instance with its own RPL
Sub-Ring
is connected to a Major Ring
or upper Sub-Ring via the
Interconnection Nodes and
does not constitute a closed
ring
is controlled by its own ERP
instance with its own RPL
Geneva, 28 May 2010
Major
Sub
Sub
Major
Sub
Sub
12
R-APS Virtual Channel
The 2010 version supports two implementation options for R-APS
control channel of the Sub-Ring.
with R-APS Virtual Channel
without R-APS Virtual Channel
In the first option, R-APS messages are encapsulated and
transmitted over an R-APS Virtual Channel configured on the Major
Ring.
In the second option, R-APS messages are terminated at the
Interconnection Nodes but not blocked at RPL of the Sub-Ring.
R-APS Virtual Channel
Major
Major
Major
Major
R-APS
Channel
Sub
Sub
Sub
Sub
Physical Ring
R-APS Channel
of Major Ring
R-APS Channel
of Sub-Ring
with R-APS
Virtual Channel
R-APS Channel
of Sub-Ring
without R-APS
Virtual Channel
Geneva, 28 May 2010
13
Administrative commands
New revision supports basic operator administrative
commands
Forced Switch (FS)
– allows operator to block a particular ring port
Effective even if there is existing SF condition
Multiple FS commands supported per ring
May be used to allow immediate maintenance operations
Manual Switch (MS)
– allows operator to block a particular ring port
Not effective if existing FS or SF condition
Overridden by new FS and SF conditions
New MS commands are ignored
Clear
– cancels an existing FS/MS command on the ring port
May be used (at RPL Owner Node) to trigger reversion
Geneva, 28 May 2010
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Multiple ERP instances
New revision supports multiple ERP instances
ERP instance is composed of a set of VLANs.
Multiple ERP instances can be configured on a same
physical ring.
ERP instance protects a subset of the VLANs that
transport traffic over the physical ring.
Each ERP instance is independent of other ring
instances.
Instance 1
Instance 2
Geneva, 28 May 2010
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R-APS message
R-APS message format (based on Y.1731 APS)
1
8
7
6
1
MEL
5
Request
/State
5
2
4
3
2
1
8
7
Version (1)
6
5
3
4
3
2
1
8
7
OpCode (R-APS = 40)
Sub-code
D
N
F
B
P
R
4
3
2
1
8
7
6
5
4
3
2
1
TLV Offset (32)
Node ID (6 octets)
Status Reserved
9
Node ID
13
Reserved 2 (24 octets)
…
…
37
5
Flags (0)
Status
R
B
6
4
[optional TLV starts here; otherwise End TLV]
last
Geneva, 28 May 2010
End TLV (0)
16
Outline
Objectives and Principles
Basic protection mechanism
Revision notes
Detailed functionality
Future work
Summary
Geneva, 28 May 2010
17
Future work item 1
End-to-end service resiliency
Resilient metro/core network can be realized by
G.8032v2, but access network is not yet supported by
ring protection. Guidelines for providing end-to-end
resilient service are under study.
Access network
G.8032
Dual node
interconnection
Access network
Geneva, 28 May 2010
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Future work item 2
Multiple failure recovery
In some cases, ring segmentation occurs due to multiple
failures. Guidelines for a mechanism to minimize its
effect are under study.
The 2010 version
under study
Major
Major
Major
Major
Sub
Sub
Sub
Sub
Normal condition
Single failure condition
Double failure condition
Moving blocked link
Geneva, 28 May 2010
19
Other future work items
Reduced consumption of VIDs
Method to reduce the number of VIDs allocated for RAPS control channel
FDB Flush optimization
Method to minimize the effect of flooding in case of
protection switching or reversion
Geneva, 28 May 2010
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Outline
Objectives and Principles
Basic protection mechanism
Revision notes
Detailed functionality
Future work
Summary
Geneva, 28 May 2010
21
Summary
G.8032 provides resilient Ethernet network by
using ring architecture.
The 2010 version supports multi-ring protection
switching with functionality such as:
Revertive/non-revertive mode
Administrative commands
Multiple ERP instances
etc…
Some additional topics are under study including:
End-to-end service resiliency
Multiple failure recovery
etc…
Geneva, 28 May 2010
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Thank you