CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini...
-
date post
21-Dec-2015 -
Category
Documents
-
view
219 -
download
3
Transcript of CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini...
![Page 1: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/1.jpg)
CS 268:Optical Networks
Ion Stoica
April 21, 2004
(Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar Kalyanaraman (RPI),Larry McAdams (Cisco))
![Page 2: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/2.jpg)
2
Big Picture
SONET
DataCenter SONET
SONET
SONET
DWDM DWD
M
Access
Long HaulAccess
MetroMetro
![Page 3: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/3.jpg)
3
Overview
Optical Transmission Dense Wavelength Division Multiplexing (DWDM) Synchronous Optical Network (SONET) Generic Framing Procedure (GFP)
![Page 4: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/4.jpg)
Optical Transmission
Waveform after 1000 kmTransmitted data waveform
![Page 5: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/5.jpg)
5
Fiber Attenuation
Telecommunications industry uses two windows: 1310 & 1550 nm
1550 window is preferred for long-haul applications
- Less attenuation
- Wider window
- Optical amplifiers
1310window
1550window
![Page 6: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/6.jpg)
6
Dispersion
Dispersion causes the pulse to spread as it travels along the fiber
Chromatic dispersion- Light propagation in material varies with the wavelength
- Degradation scales as (data-rate)2
(Figure from http://lw.pennnet.com/)
![Page 7: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/7.jpg)
7
Dispersion
Modal dispersion- Only for fiber that carry multiple light rays (modes)
- Different modes travel at different speeds
- Multimodal fiber used only for short distances
![Page 8: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/8.jpg)
8
Overview
Optical Transmission Dense Wavelength Division Multiplexing (DWDM) Synchronous Optical Network (SONET) Generic Framing Procedure (GFP)
![Page 9: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/9.jpg)
9
DWDM
1310/1510 nm
1310/1510 nm
16 uncorrelated vawelengths
λ1λ2 λ3λ4 λ5 λ16
2.488 Gbps (1)
2.488 Gbps (16)
16*2.488 Gbps = 40 Gbps
1530-1565 nm ramge
16 stabilized, correlated vawelengts
![Page 10: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/10.jpg)
DWDM System Design
40-80 km
Terminal
Regenerator - 3R (Reamplify, Reshape and Retime)
Terminal
120 km
TerminalTerminal
Optical Amplifiers (OA)
Terminal
OA amplifies all s
Terminal
Terminal
Terminal
Terminal
Terminal
![Page 11: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/11.jpg)
DWDM System Design
1550
1551
1552
1553
1554
1555
1556
1557
01234567
01234567
Amplify DW
DM
Filt
er
Op
tic
al C
om
bin
er
15xx nm 1310 nmReamplifyReshapeRetime
Rx Tx1310 nm
Rx
Ex
tern
al
Mo
du
lato
r
Laser
15xx nm
![Page 12: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/12.jpg)
12
All-Optical Switching
Natively switch s while they are still multiplexed
Eliminate redundant optical-electronic-optical conversions
DWDMFibers
inDWDMDemux
DWDMDemux
DWDMFibers
outDWDM
Mux
DWDMMux
All-optical
OXC
![Page 13: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/13.jpg)
13
1-D MEMS
MEMS: Micro-electromechanical systems
1-Dimensional array of micro-mirrors
- 1 mirror per wavelength Digital control; no motors
![Page 14: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/14.jpg)
14
Optical Switch
1-input 2-outoput illustration with four wavelengths
1-D MEMS with dispersive optics - Dispersive element separates the ’s from inputs
- MEMS independently switches each - Dispersive element recombines the switched ’s into outputs
1-D MEMSMicro-mirror
Array
Digital MirrorControl
Electronics1011
Wavelength Dispersive Element
Input Fiber
Output Fiber 1
Output Fiber 2
Input & Output fiber array
![Page 15: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/15.jpg)
15
Optical Switch
2 in
4 in
5 in
7 in
N in
1 out
2 out
4 out
5 out
7 out
N out
1drop
2drop
3drop
4drop
5drop
6drop
7drop
Mdrop
1add
2add
3add
4add
5add
6add
7add
Madd
...
...
......
Tunable lasers
1 in
Wavelength-multiplexer N x M
four-portoptical matrix
switch
3 in 3 out
6 out6 in
![Page 16: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/16.jpg)
16
Optical Add-Drop Multiplexer
Add-drop one Each is associated with a fixed add/drop port Used to implement ring topologies
... ...
...
...
...
DE
MU
X
MU
X
![Page 17: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/17.jpg)
17
Overview
Optical Transmission Dense Wavelength Division Multiplexing (DWDM) Synchronous Optical Network (SONET) Generic Framing Procedure (GFP)
![Page 18: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/18.jpg)
18
SONET
Encode bit streams into optical signals propagated over optical fiber
Uses Time Division Multiplexing (TDM) for carrying many signals of different capacities
- A bit-way implementation providing end-to-end transport of bit streams
- All clocks in the network are locked to a common master clock
- Multiplexing done by byte interleaving
![Page 19: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/19.jpg)
19
Synchronous Transport Signal (STS)
First two bytes of each frame contain a special bit pattern that allows to determine where the frame starts
Receiver looks for the special bit pattern every 810 bytes
- Size of frame = 9x90 = 810 bytes
90 columns
9 ro
ws
Data (payload)overhead
SONET STS-1 Frame
Synchronous Payload Envelope (SPE)
![Page 20: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/20.jpg)
20
Encoding
Overhead bytes are encoded using Non-Return to Zero- high signal 1; low signal 0
To avoid long sequences of 0’s or 1’s the payload is XOR-ed with a special 127-bit patter with many transitions from 1 to 0
- Duration of a frame is 125 µsec (51.84 Mbps for STS-1)
![Page 21: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/21.jpg)
21
SONET Overhead Processing
Three layers of overhead- Path overhead (POH): end-to-end transport
- Line overhead (LOH): mux-to-mux transport
- Section overhead (SOH): adjacent network element
MU
X
IntermediateMultiplexer(ADM or DCS)
Regenerator Regenerator
Section Section Section Section
Line Line
Path
DE
MU
X
![Page 22: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/22.jpg)
22
STS-1 Frame Format
Two-dimensional: 9*80 = 810 bytes Time Frame: 125 µsec Rate: 810*8 bit/125 µsec = 51.84 Mbps For STS-3 only the number of columns changes
(3*80 = 270)
90 Bytes90 BytesOr “Columns”Or “Columns”
99RowsRows
Small Rectangle =1 Byte
![Page 23: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/23.jpg)
23
STS-1 Headers
90 Bytes90 BytesOr “Columns”Or “Columns”
99RowsRows
Section Overhead (SOH)
Line Overhead (LOH)Path Overhead (POH): Floating; can begin anywhere
![Page 24: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/24.jpg)
24
Section Overhead (SOH)
First 3 lines in the header Main functions
- Framing (A1, A2)
- Monitor performance
- Local orderwire (E1): select repeater/terminal within communication complex
- Proprietary OAM (Operation, Administration, and Maintenance) (F1)
SOH
3 B 87 B
A1=0xF6
A2A2=0x28=0x28
J0/Z0J0/Z0STS-IDSTS-ID
B1B1BIP-8BIP-8
E1E1OrderwireOrderwire
F1F1UserUser
D1D1Data ComData Com
D2D2Data ComData Com
D3D3Data ComData Com
![Page 25: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/25.jpg)
25
Line Overhead (LOH)
Last 3 lines in the header Main functions
- Locating payload (SPE) in the frame (H1, H2)
- Muxing and concatenating signals
- Performance monitoring
- Automatic protection switch (K1, K2)
• Switchover in case of failure
- Line maintenanceLOH
3 B 87 B
H1H1PointerPointer
H2H2PointerPointer
H3H3Pointer ActPointer Act
B2B2BIP-8BIP-8
K1K1APSAPS
K2K2APSAPS
D4D4Data ComData Com
D5D5Data ComData Com
D6D6Data ComData Com
D7D7Data ComData Com
D8D8Data ComData Com
D9D9Data ComData Com
D10D10Data ComData Com
D11D11Data ComData Com
D12D12Data ComData Com
S1S1SyncSync
M0M0REIREI
E1E1OrderwireOrderwire
![Page 26: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/26.jpg)
26
Path Overhead (POH)
1st column in SPE Main functions
- Info about SPE content
- Performance monitoring
- Path status
- Path trace SPE can start anywhere in
the current frame and span the next one
- Avoids buffer management complexity & artificial delays 1st STS-1
2nd STS-1
POH
9 rows
J1J1TraceTrace
B3B3BIP-8BIP-8
C2C2Sig LabelSig Label
G1G1Path StatPath Stat
F2F2UserUser
H4H4IndicatorIndicator
Z3Z3GrowthGrowth
Z4Z4GrowthGrowth
Z5Z5TandemTandem
SPE
![Page 27: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/27.jpg)
27
STS-N Frame Format
Composite Frames:Composite Frames:• Byte InterleavedByte Interleaved STS-1’s STS-1’s• Clock RateClock Rate = Nx51.84 Mbps = Nx51.84 Mbps• 9 colns overhead9 colns overhead
90xN Bytes90xN BytesOr “Columns”Or “Columns”
N Individual STS-1 FramesN Individual STS-1 Frames
ExamplesExamples STS-1STS-1 51.84 Mbps 51.84 Mbps
STS-3STS-3 155.520 Mbps 155.520 MbpsSTS-12STS-12 622.080 Mbps 622.080 MbpsSTS-48STS-48 2.48832 Gbps 2.48832 GbpsSTS-192 9.95323 GbpsSTS-192 9.95323 Gbps
Multiple frame streams, w/ independent payload pointersNote: header columns also interleaved
![Page 28: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/28.jpg)
28
STS-N: Generic Frame Format
STS-1 STS-N
![Page 29: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/29.jpg)
29
STS-Nc Frame Format
Concatenated mode:Concatenated mode:• Same header structure and data rates as Same header structure and data rates as STS-NSTS-N• Not all header bytes usedNot all header bytes used• First H1, H2 Point To POHFirst H1, H2 Point To POH• Single PayloadSingle Payload In Rest Of SPE In Rest Of SPE
90xN Bytes90xN BytesOr “Columns”Or “Columns”
Transport Overhead: Transport Overhead: SOH+LOHSOH+LOH
Current IP over SONET technologies use concatenated mode: OC-3c (155 Mbps) to OC-192c (10 Gbps) ratesa.k.a “super-rate” payloads
![Page 30: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/30.jpg)
30
Practical SONET Architecture
ADM – Add-Drop MultiplexerDCS – Digital Crossconnect
![Page 31: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/31.jpg)
31
Protection Technique Classification
Restoration techniques can protect the network against:- Link failures
• Fiber-cables cuts and line devices failures (amplifers)
- Equipment failures
• OXCs, ADMs, electro-optical interface. Protection can be implemented
- In the optical channel sublayer (path protection)
- In the optical multiplex sublayer (line protection) Different protection techniques are used for
- Ring networks
- Mesh networks
![Page 32: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/32.jpg)
32
1+1 Protection
Traffic is sent over two parallel paths, and the destination selects a better one
In case of failure, the destination switch onto the other path Pros: simple for implementation and fast restoration Cons: waste of bandwidth
![Page 33: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/33.jpg)
33
1:1 Protection
During normal operation, no traffic or low priority traffic is sent across the backup path
In case failure both the source and destination switch onto the protection path
Pros: better network utilization Cons: required signaling overhead, slower restoration
![Page 34: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/34.jpg)
34
1:1 Ring Protection
Each channel on one ring is protected by one channel on the other ring
When faults loop around
ADM
ADM
ADM ADM
ADM
ADM
ADM ADM
![Page 35: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/35.jpg)
35
Protection in Ring Network
1+1 Path Protection
Used in access rings for traffic aggregation
into central office
1:1 Line Protection
Used for interoffice rings
1:1 Span and Line Protection
Used in metropolitan or long- haul rings
(Unidirectional Path Switched Ring)
(Bidirectional Line Switched Ring)
![Page 36: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/36.jpg)
36
Protection in Mesh Networks
Working Path
Backup Path
Network planning and survivability design - Disjoint path idea: service working route and its backup route are
topologically diverse.
- Lightpaths of a logical topology can withstand physical link failures.
![Page 37: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/37.jpg)
37
Path Switching: restoration is handled by the source and the destination.
Normal Operation
Line Switching: restoration is handled by the nodes adjacent to the failure. Span Protection: if additional fiber is available.
Line Switching: restoration is handled by the nodes adjacent to the failure.
Line Protection.
Path Protection / Line Protection
![Page 38: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/38.jpg)
38
Shared Protection
1:N Protection
Backup fibers are used for protection of multiple links Assume independent failure and handle single failure. The capacity reserved for protection is greatly reduced.
Normal Operation
In Case of Failure
![Page 39: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/39.jpg)
39
Overview
Optical Transmission Dense Wavelength Division Multiplexing (DWDM) Synchronous Optical Network (SONET) Generic Framing Procedure (GFP)
![Page 40: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/40.jpg)
40
Generic Framing Procedure (GFP)
GFP provides a generic mechanism to adapt traffic from higher-layer client signals over an octet synchronous transport network (e.g., SONET)
GFP – Common Aspects (Payload Independent)
GFP – Client Specific Aspects (Payload Dependent)
Ethernet IP/PPP Other Client Signals
SONET/SDH VC-n Path
OTN ODUk Path
Other octet-synchronous
paths
![Page 41: CS 268: Optical Networks Ion Stoica April 21, 2004 (Based in part on slides from Ed Bortolini (Network Photonics), Ling Huang (UC Berkeley), Shivkumar.](https://reader030.fdocuments.net/reader030/viewer/2022032704/56649d555503460f94a31dbe/html5/thumbnails/41.jpg)
41
Generic Framing Procedure (GFP)
Frame-mapped- Need to know the client protocol
- Associate a length to each higher level frame
- Efficient: eliminate the need for byte stuffing or for block encoding (e.g., 8B/10B)
Transparent- No need to know the client protocol
- Less efficient; can transmit signal even when the client is idle