PHY Layer Monitoring
Chiwu Ding, Zeng Li, and WB Jiang
HUAWEI TECHNOLOGIES Co., Ltd.
IEEE 802.3ba Task Force, 2008
Page 3
Outline
• PHY monitoring in 10GE
• 100GE PHY Monitoring
–Improvement to multi-lane architecture
• Detailed discussion on 100GE PHY Monitoring
–PHY OAM block definition
–Transmission mechanism of PHY OAM
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
Page 4
PHY Monitoring in 802.3ae
•
There is a Link Fault Signaling mechanism in 10GE
– Reside in Reconciliation Sublayer (RS)
– To monitor link status between local RS & remote RS and perform link status
notification
– Sublayers within the PHY are required to detect faults that render a link unreliable
High Layer
High Layer
MAC
RS
XGMII
LF
PHY
MDI
MAC
LF: Local Fault
RS
RF
Faults detected between
the remote RS and the
local RS
RF
PCS
WIS (Optional)
PMA
PMD
RF
PCS
WIS (Optional)
PMA
PMD
RF: Remote Fault
RF signal originated at
RS when detects LF
RF
RF
IEEE 802.3ba Task Force, 2008
RF
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Page 5
PHY Monitoring in 802.3ae
• Link fault status covers all possible defects detected between
local RS and remote RS
– I/O Signal Detect
– Protocol Detect, includes:
•
•
•
•
CODEC Synchronization
Lane Alignment (Multi-Lane Only, 10GBASE-X)
WIS Frame/Payload Acquisition
Link Status Report Recognized
• RS reports the fault status of the link
– Local Fault indicates a fault detected on the receive data path
– Remote Fault indicates a fault on the transmit path
• RS response to the link fault status
– LF: Stop sending MAC data, and continuously generate a RF status on the
transmit path when LF status reaches the RS
– RF: Stop sending MAC data, and continuously generate Idle on the transmit path
when RF status received by the RS
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
Page 6
100GE PHY Monitoring Suggestion
• Inherit Link Fault Signaling mechanism from 10GE
• Improve 100GE multi-lane architecture to provide enhanced
PHY OAM function
– Monitor each lane separately
– Distinguish between lane status and link status
• LLF: Local Lane Fault
• RLF: Remote Lane Fault
– Indicate more detailed link or lane status information for management
• Signal fault/defect, Protocol fault/defect, Synchronization error, etc.?
• Fault location indicate
– Mapping between 100GE PHY OAM and transport network OAM
– Some more functions to be considered
• BER monitor
• Auto negotiate via PHY OAM
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
Page 7
100GE PHY Monitoring Suggestion
Router
Line-card
Router
Line-card
λ
λ
OTN
Line-card
Router
Line-card
OTN
Line-card
OTN
Line-card
Router
Line-card
OTN
Line-card
4x25G xWDM
10x10G Multi-lane fiber
(4-Lane PMD)
(10-Lane PMD)
• New PCS architecture will be introduced in 100GE, and multilane PHY monitoring should be supported to per lane or per
lambda
–Independent laser monitoring (fault, performance, laser degradation)
–Improve Ethernet PHY reliability
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
Page 8
PHY OAM Process
• PHY OAM is defined as a new block type.
• Two options may be considered to transmit PHY OAM on
lane
–Insert PHY OAM by stealing from IPG without extra bandwidth
–Increase line rate to carry the PHY OAM
• Receive and notify the PHY OAM information
–Detect PHY OAM information at receive path
–Indicate PHY OAM information to upper layer
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
Page 9
What Should the OAM Block Look like?
•OAM block: 64-bit data + 4-bit ctrl
1011
0xa5
Block type:8bits
OAM type: 8bits
•x01H:LLF
•x02H:RLF
•x03H:status advertisement
•x04H:BER Monitor
•Others: reserved
Broadcast OAM / lane OAM : 2bits
lane ID : 6bits
OAM value : 24bits
reserved
IEEE 802.3ba Task Force, 2008
TXD/RXD
TXC/RXC Description
D D
D
D
D
D
D
D
0000
Data
S D
D
D
D
D
D
D
1001
Start
C C
C
C
S
D
D
D
1010
Start
T
C
C
C
C
C
C
C
1000
Terminate
D
T
C
C
C
C
C
C
0111
Terminate
D D
T
C
C
C
C
C
0110
Terminate
D D
D
T
C
C
C
C
0101
Terminate
D D
D
D
T
C
C
C
0100
Terminate
D D
D
D
D
T
C
C
0011
Terminate
D D
D
D
D
D
T
C
0010
Terminate
D D
D
D
D
D
D
T
0001
Terminate
C C
C
C
C
C
C
C
1111
Control
A A
A
A
A
A
A
A
1101
Alignment
O O O O O O O O
1011
OAM
N N
N
N
N
N
N
N
New
Null
X
X
X
X
X
X
X
New
Reserve
X
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Page 10
Insert OAM Block by Stealing from IPG
Block
Distributor
IPG Packet IPG Packet
CTBI
PCS
MAC/RS
66bit
•••
Block
Generator
IPG DC
64B/66B
encoder
scramble
64B/66B
encoder
scramble
64B/66B
encoder
scramble
Lane1
Lane2
Lane10
OAM Block
Generator
Packet IPG Packet IPG Packet IPG Packet IPG Packet IPG Packet IPG Packet IPG Packet
64B 64B •••
64B 64B 64B
••• 64B 64B 64B •••
64B 64B 64B
Continuous IPG after adjust
•
IPG adjustment gains enough bandwidth for inserted OAM
•
Introduce Deficit Counter mechanism to collect extra IPG
•
OAM blocks cover the extra IPG (generator)
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
•••
64B
Page 11
Insert OAM Block by Stealing from IPG
64B •••
64B 64B 64B
••• 64B 64B 64B •••
64B 64B
Continuous IPG after adjust
64B 64B 64B 64B 64B
64B
O
64B 64B 64B
66B
O
66B 66B 66B
64B 64B 64B 64B 64B
64B
O
64B 64B 64B
66B
O
66B 66B 66B
•••
64B 64B 64B 64B 64B
•••
64B O
64B 64B 64B
•••
66B O
66B 66B 66B
64B
IPG Block
O
OAM block before
64/66 encoding
•
Adjusts IPG together
•
Distributes IPG blocks into each lane
•
PHY OAM replaces the IPG block on each lane
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
O
OAM block after
64/66 encoding
Page 12
Insert OAM Block by Increasing Line Rate
64B 64B 64B 64B 64B 64B
64B 64B 64B 64B 64B 64B
•••
•
Line rate increased
•
PHY OAM blocks are inserted
periodically
64B 64B 64B 64B 64B 64B
O
64B 64B 64B
O
64B 64B 64B
O
66B 66B 66B
O
66B 66B 66B
O
64B 64B 64B
O
64B 64B 64B
O
66B 66B 66B
O
66B 66B 66B
O
66B 66B 66B
•••
O
64B 64B 64B
O
•••
O
64B 64B 64B
OAM block before
64/66 encoding
IEEE 802.3ba Task Force, 2008
O
66B 66B 66B
O
OAM block after
64/66 encoding
HUAWEI TECHNOLOGIES Co., Ltd.
Page 13
LLF&RLF Generation
PCS
MAC/RS
Block
Distributor
66bit
OAM (RLF)
Block
Generator
IPG DC
64B/66B
encoder
scramble
64B/66B
encoder
scramble
64B/66B
encoder
scramble
Lane1
Lane2
Lane10
OAM Block
Generator
OAM (LLF)
Block
Distributor
Block
Reassemble
Lane Status
Detector
66bit
64B/66B
encoder
scramble
64B/66B
encoder
scramble
64B/66B
encoder
scramble
Lane2
OAM Block
Detector
Detect lane unavailable, transmit a Remote Link Fault signaling on
transmitting path
IEEE 802.3ba Task Force, 2008
Lane1
HUAWEI TECHNOLOGIES Co., Ltd.
Lane10
Page 14
PHY OAM Indication
Block
Distributor
OAM
OAM
Block
Reassemble
OAM
66bit
64B/66B
encoder
scramble
64B/66B
encoder
scramble
64B/66B
encoder
scramble
Lane1
Lane2
Lane10
OAM Block
Detector
Detect OAM
information and
notify upper layer
• OAM Block Detector picks up the PHY OAM information on lane
• Notify the PHY OMA information to upper layer
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
Page 15
Conclusions
• PHY OAM providing monitoring status of a physical lane
– Lane failure will be indicated: (LLF/RLF)
– More functions may be defined by PHY OAM
• Auto Negotiate
• BER monitor
• information advertisement
• Implementation of PHY monitoring/PHY OAM
– PHY OAM will be defined in block format
– Provide lane fault detection and notification
– Two options for OAM block transmission
• Option 1: utilization of IPG space
• Option 2: increasing line rate to provide reliable and periodical OAM
transmission bandwidth
IEEE 802.3ba Task Force, 2008
HUAWEI TECHNOLOGIES Co., Ltd.
Thank You
HUAWEI TECHNOLOGIES Co., Ltd.
IEEE 802.3ba Task Force, 2008