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EETHERNETTHERNETOOVERVERSSDHDH
AGENDA
Market & Technology Drivers New SONET/SDH - Overview Virtual Concatenation (VC) Link Capacity Adjustment Scheme (LCAS) Generic Frame Procedure (GFP)
THE SITUATION
The economic situation in the Telecom Industry has changed...
...and so has the technological approach to meet new challenges!
THE FUTURE
SONET/SDHNetwork
SONET/SDH for VOICE
Services
Seen Status
One new network for both applications!
LAN
Fully RoutedOptical IPNetwork
Optical IP for DATA
Services
Future Network
THE STATUS TODAY
SDH/ SONET - is the deployed technology in the core network with huge investments in capacity!
Ethernet - is the dominant technology of choice at LANs and well known at all enterprises worldwide!
Data traffic is still growing, but only at a slower speed than expected
All network topologies focusing on a IP/Ethernet ONLY approach are shifted to long-term future.
The future today:
Bring SDH and Ethernet together!
NEW NETWORK REQUIREMENTS
Storage Area Network (SAN)
Virtual Private Network(VPN)
Edge Network
Core Network
Storage Server
LAN LANPC
Server
SONET/SDH
Ethernet
Fibre Channel
BRINGING IT ALL TOGETHER
Operator wants:• Reduce Operational Expenses• Realize revenue-earning services• Use bandwidth of Core Network• Low investment immediate Returns• Close the edge bottleneck!
X
Customer expects:• QoS & BW at low costs• Native Data Interfaces• Use & Improve what he knows!
Edge
Core
Ethernet IF
LAN
Fiber Channel IF
SAN
Voice
NNext ext GGenerationenerationSSDHDHOOverviewverview
VC
GFP
LCAS
LAPS
Ethernet
GOING INTO DETAILS
Let‘s zoom in!
Campus A
Ethernet
Optical CoreOptical Core
NetworkNetwork
Remote Servers
Storage Servers
Fibre Channel
SONET/SDHSONET/SDH
DWDMDWDM
SONET/ SDH
SONET/ SDH
SONET/ SDH
Campus B
EthernetFICON
Core NE
Edge NE
SONET/SDH
SO
NE
T M
UX
/DE
MU
X
Nat
ive
In
terf
aces
NG SDH at the Edge
That’s “ NG SDH “
?VC
VirtualConcatenation
LCAS
Link Capacity
Adjustment Scheme
GFP
Generic Frame
Procedure
LAPS
Ethernet
Ficon
Escon
Fibre Channel
Edge CoreAdaptationCustomer Operator
CUSTOMER NEEDS ETHERNET
Typical Ethernet Traffic
Connections
Mbit/s
1 2 3 4
Ethernet Packet
Problem: How can we efficiently transport Ethernet over an existing SDH network?
Example: For 10M available SDH - Containers are...
VC-12 ...too small !
2.176 Mbit/s
VC-3 ... inefficient20%
48.38 Mbit/s
OR
100
25
50
75
time
Customer 3 = 100M
Customer 2 = 60M
Customer 1 = 10M
SDH LINE RATES
10 M
Transport 10M Ethernet over SDH?
C-4-4c 0.599 Gbit/sC-4-16c 2.396 Gbit/sC-4-64c 9.584 Gbit/sC-4-256c 38.338 Gbit/s
Contiguous ConcatenationContiguous Concatenationonly large containers!
C-11 1.600 Mbit/sC-12 2.176 Mbit/sC-2 6.784 Mbit/sC-3 48.384 Mbit/sC-4 149.760 Mbit/s
SDH Payload Sizes
Standard Containers are inefficient!
Can’t 5 x VC-12 be concatenated?
?5x
VVirtualirtualCConcatenationoncatenation
VC-n-X v
C-4-4c 599.040 Mbit/sC-4-16c 2.396 Gbit/sC-4-64c 9.584 Gbit/sC-4-256c 38.338 Gbit/s
Contiguous Concatenation
CONCATENATION?
Contiguous ConcatenationOffers concatenated payloads in fixed, large steps One towing truck (POH) for all containersAll containers are on one path thru the network
VC-4-4c
C4 C4 C4 C4
CONCATENATION?
Virtual ConcatenationOffers structures in a fine granularity Every container has its own towing truck (POH)Every container might take a different path
VC-4-4v
VC-4 #1VC-4 #2VC-4 #3VC-4 #4
MSOH
RSOH
AU-4 Pointer
STM-N
CC: VC-4-Xc Container
Overhead N x 9 bytes Payload N x 261 bytes
VC-4-Xc, where X=4, 16, 64, 256
VC-4-Xc
X x 261 bytes
X -11
J1
C2G1
H4
F3
K3N1
C-4-XcF
ixe
d S
tuff
B3
F2
MSOH
RSOH
AU-4 Pointer
STM-N
VC: VC-4-Xv ContainerOverhead N x 9 bytes Payload N x 261 bytes
VC-4-Xv, where X = 1..256
261 bytes1
VC-4
J1
C2G1
H4
F3
K3N1
B3
F2VC-4
J1
C2G1
H4
F3
K3N1
B3
F2VC-4
J1
C2G1
H4
F3
K3N1
B3
F2
X frames
Virtual Concatenation is standardizedwith SONET containers (ANSI T.105) orSDH containers (ITU-T G.707)
Virtual Concatenation providesa scheme to build right-sized SONET/SDH containers
Virtual Concatenation offersa very fine granularity
VIRTUAL CONCATENATION (VC OR VCAT)
VC NOMENCLATURE
VC-nVirtual Container n
n=4, 3, 2, 12, 11
Defines the type of virtual containers, which will be virtually concatenated.
-XNumber of
virtuallyconcatenated
containers
All X Virtual Containers form together the
“Virtual Concatenated Group” (VCG)
vIndictor for
Virtual Concatenation
v = virtual concatenationc = contiguous concatenation
Virtual Concatenated Group (VCG) of X VC-n containers!
HIGH AND LOW ORDER VC
High Order Virtual Concatenation• refers to virtually concatenated...
VC-4
VC-3 containers
Low Order Virtual Concatenation• refers to virtually concatenated...
VC-11
VC-12
VC-2
containers
VC-4-XV GRANULARITY
VCG Granularity
VCG Payload Capacity
Maximum
Minimum
VCGs:VC-4-1v Payload Size 149,76 Mbit/sVC-4-2v Payload Size 299,52 Mbit/s
VC-4
Example High Order VC:VC-4 Container Size 150,3 Mbit/sVC-4 Payload Size 149,76 Mbit/s
VC-4-7v Payload Size 1048,3 Mbit/s
VC-4-256v Payload Size 38338 Mbit/s
VC-12-XV GRANULARITY
Example Low Order VC:VC-12 Container Size 2,240 Mbit/sVC-12 Payload Size 2,176 Mbit/s
Minimum
VCG GranularityVCGs:VC-12-1v Payload Size 2,176 Mbit/sVC-12-2v Payload Size 4,352 Mbit/s
VCG Payload Capacity
Maximum
VC-12-5v Payload Size 10,88 Mbit/s
VC-12-64v Payload Size 139,26 Mbit/s
VC-12
VC GRANULARITY AND MAX. CAPACITY
NomenclatureGranularityMax. Capacity
VC-4 –n v 149 M - 38.3G
VC-3 –n v 48 M - 12.7 G
VC-2 –n v 6.8 M - 434 M
VC-12 –n v 2.2 M - 139 M
VC-11 –n v 1.6M - 102 M
VC-4
VC-3
VC-2
VC-12
VC-11
Maximum Concatenation: = 256 containersMax. Capacity: = 256 x granularity
VC RATE EFFICIENCIES
Ethernet (10M) VC3 20% VC-12-5v 92%
100M Ethernet STM-1= 64 x VC-12
VC-12-5v
VC-12-46v
2x 10M Ethernet VC-12-5v
8x E1 Services
Example:
More services integrated- by using VC!
Fast Ethernet (100M) VC-4 67% VC-12-46v 100%
Data Rates Efficiency w/o VC USING VC
Gigabit Ethernet (1G) VC-4-16c 42% VC-4-7v 85%
ESCON (200M) VC-4-4c 33% VC-3-4v 100%
Fibre Channel (800M) VC-4-16c 33% VC-4-6v 89%
TRANSPORTING CONCATENATED SIGNALS
VC-4-2v
VIRTUAL CONCATENATION
VC-4 #2
VC-4 #1
VC-4 #1
Path 2
Path 1
VC-4 #2
Differential Delay
VC-4 #2
VC-4 #1
VC-4 #2
VC-4 #1
CONTIGUOUS CONCATENATION
VC-4-4c
C-4 C-4
C-4 C-4
C-4 C-4
C-4 C-4 NENE
One Path
C-4 C-4
C-4 C-4
Core Network
VVirtualirtualCConcatenationoncatenationTechnical Technical DetailsDetails
VIRTUAL CONCATENATED GROUPS
Answer:The containers do not know it!That’s the job of the network management!
Question:How does a container know that it belongs to a VCG?
Question: Which containers can belong to the same group?
Answer: They must all start at one port! And they must all end at one port!
A
B
A
B
A A
VIRTUAL CONTAINER INDICATOR
Problem:How to distinguish between VCG members of one group?
SQ=0
SQ=1
SQ=2
SQ=3
Solution:Give each member an individual “number plate”! Sequence Indicator (SQ)
VC-4
VC-4
VC-4
VC-4
TIME STAMP MECHANISM
VC-4
VC-4
VC-4
VC-4
Problem:How do we know that members arriving together started together?
Solution:Give each VCG an individual number
Frame Counter (FC)
FC = 1
SQ=0
SQ=1
SQ=2
SQ=3
FC = 0
SQ=0
SQ=1
SQ=2
SQ=3
FC = 2
SQ=0
SQ=1
SQ=2
SQ=3
FC = 3
SQ=0
SQ=1
SQ=2
SQ=3
Storage
VCG REALIGNMENT
DemappingArrival
SQ = 1FC = max
SQ = 0FC = max
SQ = 3FC = max
SQ = 1FC = max
SQ = 0FC = max
SQ = 3FC = max
SQ = 1FC = 0
SQ = 0FC = 0
SQ = 2FC = max
SQ = 3FC = 0
SQ = 1FC = max
SQ = 0FC = max
SQ = 2FC = max
SQ = 3FC = max
SQ = 1FC = 0
SQ = 0FC = 0
SQ = 3FC = 0
SQ = 1FC = 1
SQ = 0FC = 1
SQ = 3FC = 1
SQ = 1FC = max
SQ = 0FC = max
SQ = 2FC = max
SQ = 3FC = max
SQ = 1FC = 0
SQ = 0FC = 0
SQ = 3FC = 0
SQ = 2FC = 0
SQ = 1FC = 1
SQ = 0FC = 1
SQ = 3FC = 1
SQ = 1FC = max
SQ = 0FC = max
SQ = 2FC = max
SQ = 3FC = max
SQ = 1FC = 0
SQ = 0FC = 0
SQ = 3FC = 0
SQ = 2FC = 0
SQ = 1FC = 1
SQ = 0FC = 1
SQ = 3FC = 1
SQ = 1FC = 2
SQ = 0FC = 2
SQ = 2FC = 1
SQ = 3FC = 2
SQ = 1FC = 0
SQ = 0FC = 0
SQ = 3FC = 0
SQ = 2FC = 0
SQ = 1FC = 1
SQ = 0FC = 1
SQ = 3FC = 1
SQ = 1FC = 2
SQ = 0FC = 2
SQ = 2FC = 1
SQ = 3FC = 2
SQ = 1FC = 0
SQ = 0FC = 0
SQ = 3FC = 0
SQ = 2FC = 0
SQ = 1FC = 1
SQ = 0FC = 1
SQ = 3FC = 1
SQ = 1FC = 2
SQ = 0FC = 2
SQ = 2FC = 1
SQ = 3FC = 2
SQ = 1FC = 3
SQ = 0FC = 3
SQ = 3FC = 3
SQ = 2FC = 2
Stop
SQ=2 is one frame late!
DIFFERENTIAL DELAY
Problem:Each individual container of a VCG might take a different route through the network - Delay?
Result: Differential Delay Different physical path lengths will result in different path delays for individual containers!
Propagation Delay (optical fiber):is approximately 5 µs/km 1000km extra path length = 5ms Differential Delay Once around the earth Extra (42.000km) = 210ms DD
Solution:A container storage & realignment process is necessaryto compensate for differential delay!
How the group starts:
Network
How the group arrives:
Storage Demapping
Differential Delay ExampleExample:VC-4-2v group routed over TWO paths• Container SQ=0 1000km 5.0 ms propagation time• Container SQ=1 1075km 5.375 ms propagation time Differential Delay = 5.375ms-5.0ms = 0.375ms (=3 frames)
SQ = 0FC = 0
SQ = 1FC = 0
SQ = 0FC = 0
SQ = 1FC = 0
SQ = 0FC = 1
SQ = 1FC = 1
SQ = 0FC = 0
SQ = 1FC = 0
SQ = 0FC = 1
SQ = 1FC = 1
SQ = 0FC = 2
SQ = 1FC = 2
SQ = 0FC = 0
SQ = 1FC = 0
SQ = 0FC = 1
SQ = 1FC = 1
SQ = 0FC = 2
SQ = 1FC = 2
SQ = 0FC = 3
SQ = 1FC = 3
SQ = 0FC = 0
SQ = 1FC = 0
SQ = 0FC = 1
SQ = 1FC = 1
SQ = 0FC = 2
SQ = 1FC = 2
SQ = 0FC = 3
SQ = 1FC = 3
SQ = 0FC = 4
SQ = 1FC = 4
SQ = 0FC = 0
SQ = 0FC = 0
SQ = 0FC = 1
SQ = 0FC = 0
SQ = 0FC = 1
SQ = 0FC = 2
SQ = 0FC = 0
SQ = 1FC = 0
SQ = 0FC = 1
SQ = 0FC = 2
SQ = 0FC = 3
SQ = 0FC = 0
SQ = 1FC = 0
SQ = 1FC = 1
SQ = 0FC = 1
SQ = 0FC = 2
SQ = 0FC = 3
SQ = 0FC = 4
SQ = 0FC = 1
SQ = 1FC = 1
SQ = 0FC = 2
SQ = 1FC = 2
SQ = 0FC = 3
SQ = 0FC = 4
SQ = 0FC = 5
SQ = 0FC = 2
SQ = 1FC = 2
SQ = 0FC = 3
SQ = 1FC = 3
SQ = 0FC = 4
SQ = 0FC = 5
SQ = 0FC = 6
DELAY TIMES
Problem:What’s the maximum differential delay time?
FC = 0
SQ=0
FC = 0
SQ=1
FC = 1
SQ=0
FC = 1
SQ=1
FC = max
SQ=0
FC = max
SQ=1
FC = 2
SQ=0
FC = 2
SQ=1
FC = 0
SQ=0
FC = 1
SQ=0
FC = max
SQ=0
FC = 2
SQ=0
FC = 0
SQ=1
FC = 1
SQ=1
FC = max
SQ=1FC = max-1
SQ=1
Total Differential Delay Time (s) = 1 x Frame Repetition Rate
No DelayBoth containers
arrive at the same time!
Container SQ=1arrives with
ONE frame delay
MAX. DELAY COMPENSATION
FC = 0
SQ=0FC = 1
SQ=0FC = max
SQ=0
FC = 0
SQ=1FC = 1
SQ=1FC = max
SQ=1
Maximum Differential Delay Time = FC = max x Frame Repetition Rate
FC = 0
SQ=0FC = 1
SQ=0FC = max
SQ=0FC = 2
SQ=0
FC = 0
SQ=1FC = 1
SQ=1FC = max
SQ=1FC = 2
SQ=1
Member SQ=0 and SQ=1 did not start at the same timePayload is LOST!
FC=max frames delay of SQ=1
FC = 0
SQ=1
Too much DelayFC = max+1 frames
VCG is out of synch!
WHERE ARE THE VC BYTES?
•Carried in one bit in K4-Byte 32 frame Multi-Frame
High Order VC Low Order VC• Information in H4 Byte 16 frame Multi-Frame
F2H4F3K3
B3C2G1
J1
N1
VC-3 / VC-4out of
VC-3-Xv / VC-4-Xv
J2N2K4
V5 VC-2 / VC-11/VC-12out of
VC-2-Xv / VC-11-Xv /VC-12-Xv
WHAT’S A MULTI-FRAME?
J2N2K4
V5 VC-2 / VC-11/VC-12out of
VC-2-Xv / VC-11-Xv /VC-12-Xv
Low Order VC
Frame Counter
(FC)
Sequence Indicator
(SQ)Reserved...
How to build a multi-frame control packet?• Filter from each K4 byte only bit no. 2• Store bit no. 2• After 32 VCs, one Virtual Concatenation • control information was received.
1
K4
b2 Filter
2
32x K4
b2
3
K4
b2
4
K4
b2
5
K4
b2
6
K4
b2
7
K4
b2
8
K4
b2
9
K4
b2
11
K4
b2
12
K4
b2
13
K4
b2
14
K4
b2
15
K4
b2
16
K4
b2
10
K4
b2
17
K4
b2
18
K4
b2
19
K4
b2
20
K4
b2
21
K4
b2
22
K4
b2
23
K4
b2
24
K4
b2
25
K4
b2
27
K4
b2
28
K4
b2
29
K4
b2
30
K4
b2
31
K4
b2
32
K4
b2
26
K4
b2
...for LCAS
High Order VC - H4 byte
0123456789
101112131415
MFI1 MFI2
n
H4 Byte Multi-FrameBit 1 - 4 Bit 5 - 8
Reserved “0000”Reserved “0000”
Reserved “0000”
Reserved “0000”
Reserved “0000”
Reserved “0000”
Reserved “0000”Reserved “0000”Reserved “0000”
Reserved “0000”Reserved “0000”
Reserved “0000”
MFI1 (bit 1-4)
0 0000 1000 0100 1100 0010 1010 0110 1111 0001 1001 0101 1101 0011 1011 0111 111
MFI2 (bit 1-4)MFI2 (bit 5-8)
8 bit
SQ (bit 1-4)SQ (bit 5-8)8 bit
Time for transmitting ONE multi-frame: 16 byte x 125µs = 2ms
MFI 1 - Multi Frame Indicator 14 bits - Counter incremented at each individual frameOne MFI1 multi-frame = 16 framesCounts from 0 to 15
MFI 2 - Multi Frame Indicator 28 bits - Counter incremented every 16 frames - after a complete MFI1 multi-frameCounts from 0 to 255
High Order VC Frame Counter:MFI1 x MFI2 = 16 x 255 = 4096Max. tolerable Differential Delay = 4096 x 125 µs = 512ms
SQ - Sequence Indicator8 bits - Transmitted once every MFI 1 multi-frameMax. number of High Order VCG members = 256
HIGH ORDER VC - H4 BYTE
LOW ORDER VC - K4 BYTE
K4 byte (VC-2, 11, 12)
bit 1:Extended Signal label - 32 frame multi-frame
bit 2: Low order Virtual concatenation
bit 2: 32 frame MF should be in phase with b1 multi-frame
1 72 3 4 5 6 8 9 1210 11 13 1914 15 16 17 18 20 21 2422 23 25 3126 27 28 29 30 32
ReservedMFAS = Multiframe
alignment bits0111 1111 110
Extended Signal Label 0
1 72 3 4 5 6 8 9 1210 11 13 1914 15 16 17 18 20 21 2422 23 25 3126 27 28 29 30 32
Reserved = 0Frame Count (FC)
Sequence Indicator (SQ)
Time for transmitting ONE multi-frame:Length of MF x Frame Repetition Rate32 bit x 500µs = 16ms
Low Order VC Frame Counter:FC x Length of Multi-Frame x Frame Repetition RateMax. tolerable Differential Delay = 32 x 32 x 500µs = 512ms
FC - Multi Frame Indicator5 bits - Counter incremented with each 32 bit multi-frameCounts from 0 to 31
LOW ORDER VC - K4 BYTE
SQ - Sequence Indicator6 bits - Transmitted once every 32 bit multi-frameMax. number of Low Order VCG members = 64
Low Investmentdeployment only on customer demand Fast ROI
VCBENEFITS
EconomicalRe-use core network equipment invest only at the edge
Well-knownSONET/SDH is
well engineered & reliable & trained
Efficient & Scalable
Fine granularity & multi-path
capability
VIRTUAL CONCATENATION BENEFITS
CHALLENGES AHEAD...
How can path bandwidth be increased or decreased? Dynamic Bandwidth Provisioning“..bring an additional truck on the road..”
VC-3 #1VC-3 #2
VC-3 #?
VC-4 #1VC-4 #3
VC-4 #2
FAILED
How can we ensure QoS for data services? VCG - Protection one VC container fails - the whole Virtual
Concatenation Group (VCG) fails!
LLINKINKCCAPACITYAPACITYAADJUSTMENTDJUSTMENTSSCHEMECHEME
LCAS OVERVIEW
Extension for Virtual Conc. carried in
H4/K4 byte
Add/Remove bandwidth uninterrupted
Standardized ITU-T G.7042, referred by ANSI
LinkCapacity
AdjustmentScheme
End-to-endReal-Time
Communication
HandshakeProtocolbetween edge NE
VC & LCAS CONTROL PACKET
Frame Counter
MFI
VCGSequence Indicator
SQ
VirtualConcatenation
Information
LCASError
Protection
CRC
LCASMember
Status
MST
LCASControl
Commands
CTRL
LCASSource
Identifier
GID
LCASResequence
Acknow-ledgement
RS-Ack
LCAS Information
Information Packets exchanged between the two edge network elements to adjust
the bandwidth.
CONTROL PACKET OVERVIEW
Information Direction
Source Sink
MFI Multi-Frame Indicator is an counter• to distinguish several VCGs* from each other• necessary to compensate for Differential Delay
SQSequence Indicator is an counter• to differentiate individual VC-n containers within a VCG*• to re-sequence VC-n containers at the termination point in case that differential delay occured
CTRL LCAS Control Words are• the actual commands which will show the status of containers from a VCG* initiate bandwidth changes• FIXED - container in NON-LCAS mode• ADD - container which will be added to a VCG• REMOVE - container which will be removed from a VCG• NORM - container as part of an active VCG• EOS - last container of an active VCG• DNU - container with failures(“do not use”)
*VCG = Virtual Concatenated Group
CONTROL PACKET OVERVIEW
GIDGroup Identification Bit is• an additional verification mechanism to secure that all incoming VCG members belong to one group
CRCCyclic Redundancy Check is a• protection mechanism to detect bit errors in the Control Packet
MSTMember Status Field is• an mechanism, where the sink reports to the source which VCG members are currently and correctly received
RS-AckRe-sequence acknowledgement is• an mechanism, where the sink reports to the source the detection of any additions/removals to/from the VCG
*VCG = Virtual Concatenated Group
WHERE ARE THE LCAS BYTES?
J2N2K4
V5VC-2 / VC-11/VC-12
out ofVC-2-Xv / VC-11-Xv /VC-12-Xv
F2H4F3K3
B3C2G1
J1
N1
VC-3 / VC-4out of
VC-3-nv / VC-4-nV
*CP = Control Packet
• LCAS info aligned with VC info• Carried in one bit in K4-Byte
• 32 frame Multi-Frame
High Order LCAS Low Order LCAS• LCAS info aligned with VC info• Information also in H4 Byte• 16 frame Multi-Frame
MST - Member status field8 bits - Status of 8 VCG members is reported per control packetReport time for all 63 member statuses: 128ms128 ms = 8 packets x 16ms control packet time
GID - Group Identification Bit1 bit - per 32 bit multi-frame Content is a PRBS 215-1Receiver does not have to synchronize to PRBS
CTRL - LCAS Control Words4 bits - with six possible control words currently definedOne control word is transmitted per 32 bit multi-frame
LOW ORDER LCAS - K4 BYTE
RS- Ack - Re-Sequence Acknowledgement1 bit - Transmitted once every 32 bit control packet
CRC - Cyclic Redundancy Check3 bits - to detect errors in a control packet
GID - Group Identification Bit1 bit - per multi-frame Content is a PRBS 215-1Receiver does not have to synchronize to PRBS
CTRL - LCAS Control Words4 bits - with six possible control words currently definedOne control word is transmitted per multi-frame (16x H4)
HIGH ORDER LCAS - H4 BYTE
RS- Ack - Re-Sequence Acknowledgement1 bit - Transmitted once every multi-frame
MST - Member status field8 bits - Status of 8 VCG members is reported per multi-frameReport time for all 256 member statuses: 64ms64 ms = 256/8 x 2ms control packet time
CRC - Cyclic Redundancy Check8 bits - to detect errors in a control packet
“ADD” EXPLAINED
Request from NMS to increase bandwidth on a existing link.1SourceActions for the currently unequipped container:a) assign a valid sequence indicator (SQ=currently highest +1)b) change CTRL=ADD (from CTRL=IDLE)
2Source
Sink replies with MST=OK after detection of the new member3Sink
Sink acknowledges the new status with the beginning of the next multi-frame (RS-Ack toggles)4Sink
With reception of acknowledgement source will changea) the status of the last member from CTRL=EoS to NORMb) the status of the new member from CTRL=IDLE to EoS
5Source
After the reception of the new member with CTRL=EoS Sink will start the demapping process with the next container!7Sink
Source starts to map payload information in the next upcoming container6Source
LLinkinkFFailureailure
Sink detects an failure of one memberSink changes the member status of this member to FAILOn detection of this new member status Source will set CTRL from NORM or EoS to DNU (Do not use) Sink does not demap the payload anymore.
TEMPORARY FAILURE
Sink detects the clearance of the failure statusSink sets the member status of this member to OKOn detection of this new member status Source will set CTRL to NORM or EOS againSink will now demap the payload anymore.
LINK CAPACITY ADJUSTMENT SCHEME
LCASBENEFITS
Flexible & scalableOffers variable VC bandwidth in real-time!
Cost EfficientNew NE necessary
only at the edgeTransparent to
core network
Enables Value added servicesBandwidth on demand”Soft” Protection99.999% up-time
RestorationVirtual Concatenation
link protection & recovery
GGenericenericFFrameramePProcedurerocedure
NEW SONET/SDH AT THE Edge
SONET/SDH
SO
NE
T M
UX
/DE
MU
X
Nat
ive
In
terf
aces
?
That’s “ New SONET/SDH “
VC
VirtualConcatenation
LCAS
Link Capacity
Adjustment Scheme
GFP
Generic Frame
Procedure
LAPS
Ethernet
Ficon
Escon
Fibre Channel
Edge CoreAdaptation
Customer Operator
SANs
ATM
FIC
ON
ES
CO
N
Ethernet
DV
I
HDLC
Frame Relay POS
DATA (IP, IPX, MPLS,...)
RPR
Fiber
GFP-T
Fib
re C
hann
el
SONET/SDH
WDM / OTN
Voice Video
PrivateLines
GFP-FGFP
THE BIG PICTURE
GFP - LAYER MODEL
GFP - Client Specific Aspects (payload dependent)
GFP - Common Aspects (payload independent)
SONET/SDH VC-n Path
OTN ODUk Path
Others(e.g. Fibre)
Ethernet IP/PPP Fibre Channel OthersClients
GFP
Transport
Frame Mapped Transparent Mapped
ESCON
GENERIC FRAME PROCEDURE
G.7041 Generic Frame Procedure defines
Client encapsulation - for transport over SONET/SDH or OTN networks
Frame formats - for various clients
Mapping Procedures - for client signals into GFP
Why do we need a new framing procedure?simple and scalable traffic adaptation for different
transport rates
flexible approach for data transmission which requires stringent delay, QoS
SStructure tructure ooff GGFP - FP - FFramesrames
GFP FRAME OVERVIEW
PayloadArea
8 bit
Core Header
GFP Payload Area transports higher layer specific information Length 4 to 65535 byte
Client Payload Field contains client frames (GFP-F) orclient characters (GFP-T)
ClientPayload
Information
Payload Headers gives type of client and supports client specific management procedures Includes CRC detection & correction Length 4 to 64 bytePayload
Headers
Core Header contains the length of the payload area and start of frame info and CRC-16 error detection & correction Length 4 byte
Optional Payload FCS protects the client payload information field CRC-32 Length 4 byte
OptionalPayload FCS
GFP gets scrambled before transmission!
GFP - PAYLOAD HEADER
Payload Type Fieldis mandatory for GFP client frames (PLI 4)
Provides information aboutcontent & format of the Client Payload Informationindicates different GFP frame typesdistinguishes between different services in a multi-service environment
Payload Type
ExtensionHeader
Field
PayloadArea
Core Header
ClientPayload
Information
PayloadHeaders
OptionalPayload FCS
GFP - PAYLOAD HEADERPTI - Payload Type Identifier3-bit field, which indicates the type of GFP client frameCurrently definedPTI = 000 Client DataPTI = 100 Client ManagementPTI = Others Reserved
PFI - Payload FCS Indicator1-bit field indicates the PFI = 1 PresencePFI = 0 Absenceof the optional payload Frame Check Sequence (pFCS) field
EXI - Extension Header Identifier4-bit field indicates the format of the Extension Header FieldCurrently definedEXI = 0000 Null Extension HeaderEXI = 0001 Linear FrameEXI = 0010 Ring FrameEXI = Others Reserved
PayloadType
ExtensionHeader
Field
PTI PFI EXIUPI
tHECtHEC
1
1
1
1
1 2 3 4 5 6 7 8
GFP - Payload Header
UPI - User Payload Identifier8-bit field identifies the type of client/service encapsulated in the GFP Client Payload FieldInterpretation of UPI values is different for
Client data frames (PTI=000) or Client management frames (PTI=100)
More details on the next slides
tHEC - Type Header Error Control16-bit error control codeto correct one bit error orto detect multiple bit errors in the payload type field
PayloadType
ExtensionHeader
Field
PTI PFI EXIUPI
tHECtHEC
1
1
1
1
1 2 3 4 5 6 7 8
GGFP - FP - OOperationperationMModesodes
GFP OPERATION MODES
GFP IDLE Frame: Rate Adaptation (“stuffing”)
GFP Management Frame: under study
GFP-T (Transparent Mapped): Client characters are directly mapped in GFP-T frames e.g. Fibre Channel Fixed length GFP frames Minimal Latency
00
GFP-F (Framed Mapped): For packet oriented clients, e.g. Ethernet One Client Packet = packed in one GFP frame (1:1) Minimal overhead
GFP OPERATION MODES
GFP-T
1GigE IDLELE EthEth. Frame IDLEEthernet Frame
GFP-F
Frame by Frame
GFPEthernet FrameGFP GFP GFP EthGFPGFPEth. Frame
TransparentGFP TransparentGFP TransparentGFP GFP
GFP GFP Header or IDLE frames
Block by Block
fixed
variable
GFP
GGFP - FFP - FPPayloadayloadSSpecificspecifics
ETHERNET MAC PAYLOAD46 ... 1500 Byte
7+1 Byte
Preamble
4 Byte
CRC
Payload
(und ggf. Padding)
6 Byte
Source
Address
6 ByteDest.
Address
2 Byte
Type /
Length
802.2 LLC
1Byte
DSAP
1Byte
SSAP
1Byte
CTRL
Payload
(und ggf. Padding)
802.2 SNAP
3 Byte
OUI
2 Byte
PrID
Payload(und ggf. Padding)
6 Byte
Source
Address
6 ByteDest.
Address
7+1 Byte
Preamble
4 Byte
CRC
Payload
(und ggf. Padding)
2 Byte
Type /
Length
2 Byte
Type =
8100
2 Byte
Prio, /
VLAN
8 7 6 5 4 3 2 1 0
1 0 0 10 0 0 0 0
0 0 0 00 0 0 0 0
VLAN IDENTIFIER
User Priority CFI
AA AA 03
000000 0800IP Payload
(und ggf. Padding)
GFP & ETHERNET MAC PAYLOAD
tHECType
PLIcHEC
GFP Extension Header
GFP Payload
22220-60
AsClient
Bytes
Source AddressDestination Address
PreambleStart of Frame Delimeter
Length/Type
MAC Client
Pad
Frame Check Sequence
Bytes
71
2
66
4
46-1500
Ethernet MAC Frame GFP-F Frame
Source AddressDestination Address
Length/Type
MAC Client
Pad
Frame Check Sequence
GFP & ETHERNET MAC PAYLOAD
tHECType
PLIcHEC
GFP Extension Header
GFP Payload
Source AddressDestination Address
Length/Type
MAC Client
Pad
FCS
Eth
erne
tG
FP
Hea
der
Ethernet Inter-Packet-Gaüs are deleted before encapsulation and restored after transmission Byte alignment and bit identification is maintained
ETHERNET TO GFP-FRAMED
Up to 10MEthernet Stream
5M7.5M10M
t1 2 3 42.5M
Pure Ethernet
GFP Packet Payload
Core Header
Constant Stream
ResultGFP-F Packet GFP-IDLE Packet
00hex00hex00hex00hex
Payload
cHECPLI 2
2
X
Scrambling!
GFP-FRAMED TO VC
GFP-Framed Packet Stream
5M7.5M10M
t1 2 3 42.5M
GFP StreamVC-12
#5VC-12
#4VC-12
#3VC-12
#2VC-12
#1GFP Frames
in VC containers
Transport Thru the Network
Transport
Byte-Interleaving
ETHERNET TO GFP-F SCHEME
Ethernet Control Character Termination,
e.g.
Ethernet Switch or Bridge
MAC to GFP-F Encapsulation
MAC Frame Extraction
GFP-F stream mapped to VC container
ControlTermination
VC-n orVC-n-Xv
EthernetFast EthernetGigEthernet
10Gig Ethernet
PHY-x
Ethernet Decode/Clock Recovery
ERROR HANDLING
GFP Source process detects client errors before transmission
Client packets should be discarded by the GFP processNo transmission of errored packets
GFP Source process detects client errors while in transmission
Padded up with all ones bit sequencesComplement all payload FCS (if present) and transmitResult: GFP Sink process will discard errored packetsOr Client Process will discard errored packets
GENERIC FRAME PROCEDURE
GFPBENEFITS
ReliableEasy & stabile algorithmHeader Correction
New Opportunities
Technological & Economical
Expandable with no need for
new transport equipment
Compatibleworks with basically any higher layer service and lower layer network!
