Upload
hemanta-kumar-sahoo
View
241
Download
1
Embed Size (px)
Citation preview
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
1/29
For internal circulation of BSNL only
E3E3--E4 (CFA)E4 (CFA)
Overview of SDHOverview of SDH
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
2/29
For internal circulation of BSNL only
AGENDA
SDH & PDH Hierarchy
SDH Network Survivability
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
3/29
For internal circulation of BSNL only
SynchronousAll elements are synchronized with one master
clock. DIGITALInformation is in binary.
HIERARCHYSet of bit rates in a hierarchical order.
SDH is an ITU-T Standard Technology
SDH OVERVIEW
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
4/29
For internal circulation of BSNL only
Synchronous: The digital transitions in the signalsoccur exactly at the same rate. In Synchronous
network, all the clock are traceable to one PRC,derived from a cesium atomic clock.
Plesiochronous: The digital signal transitionsoccur at almost same rate and variation remainswithin limit as per ITUT recommendation G-811. Iftwo n/w need to inter-work, their clock may bederived from two different PRC, there is a smallfrequency difference between one clock and theother.
CONCEPT OF SYNCHRONOUS,PLESIOCHRONOUS, ASYNCHRONOUS
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
5/29
For internal circulation of BSNL only
CONCEPT OF SYNCHRONOUS,PLESIOCHRONOUS, ASYNCHRONOUS
Asynchronous: Transitions of the signal doesntnecessarily occur at same nominal rate. Two
clock are derived from free-running quartzoscillators. (difference between two clock is muchgreater than a Plesiochronous difference).
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
6/29
For internal circulation of BSNL only
SDH- ADVANTAGES
1. Network simplification .
2. Reduction in the amount of equipment.
3.Multi-vender interoperability
4. Accommodating future application
5. Protection
6. NMS Functionality
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
7/29
For internal circulation of BSNL only
9 261
PAYLOAD
SO
H
270
(MATRIX REPRESENTATION)
SDH FRAME REPRESENTATION
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
8/29
For internal circulation of BSNL only
BIT RATE : STM-N
Number of Rows = 9Number of Columns = 9+261=270
Number of Bytes = 9x270Number of Bits = 9x270x8Number of Bits/Second = 9x270x8x8000
=155520000=155.520 Mbps (STM-1)
Bit Rate of STM-N = (Nx155.520) Mbps
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
9/29
For internal circulation of BSNL only
SDH NETWORK ELEMENTS
SDH Repeater
STM-n STM-n Applications:Line Signal Regenerationin Point-to-Point and RingNetworks
Terminal Multiplexer
STM-nPDH &STM-m
Tributariesm
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
10/29
For internal circulation of BSNL only
STM-1/4STM-1/4
Tributary Ports : n x 2 Mbit/s ( 34 Mbit/s)
ADM
......
WEST EAST
ADD DROP MULTIPLEXER
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
11/29
For internal circulation of BSNL only
NETWORK TOPOLOGY
TM TM
TM TMADM
* Point-To-Multipoint:
* Point-To-Point:
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
12/29
For internal circulation of BSNL only
* Ring-Topology:
NETWORK TOPOLOGY
ADM
ADM
ADM
ADM
Best Advantage of This Topology is Strong Survivability.
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
13/29
For internal circulation of BSNL only
MESH TOPOLOGY
Multiple optional rout between two nodes,complex structure ,high cost and high reliability
DXC/ADM
DXC/ADM DXC/ADM
DXC/ADM
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
14/29
For internal circulation of BSNL only
A self healing network means that a network can
automatically recover the services from a failurefault in a very short period of time without makingusers be aware of any network fault.
A Self-healing network involves no repairing andreplacement of a specific faulty component orpart but the reestablishment of communication.
SURVIVABILITY OF SDH NETWORK
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
15/29
For internal circulation of BSNL only
1. Linear ProtectionThere are three different protection scheme inLinear Protection
a. 1+1 Protection scheme (1+1 configuration)Each working line is protected by oneprotection line. The same signal is transmitted
on both lines. If a failure or degradation occur,the network elements switch the connectionover to the Protection line at the receive end.
W
P
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
16/29
For internal circulation of BSNL only
b. 1:1 Protection scheme (1:1 configuration)A protection line is used to directly replace the
working line when it fails. The protection pathcan only be used if a switchover takes place atboth the transmitting end and the receiving end.
W
P
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
17/29
For internal circulation of BSNL only
c. 1:N Protection schemeA 1:N configuration represents a more cost-effective
solution than the other two mechanisms. N workingchannels are protected by one protection channel. Ifthere are no defects in the network, this protection
channel can be used to transport low priority traffic.W
W
P
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
18/29
For internal circulation of BSNL only
Sub Network Connection (SNC) Protection:
Sub network connection protection is a pathprotection Mechanism that It is required to createtwo path for each circuit, one working and one
protection. It can be used to protect a portion of apath (e.g. that where two Separate pathsegments are available), It need not be used onall VCs within all multiplex section.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
19/29
For internal circulation of BSNL only
SDH is normally configured in a ring architecture. It is done to create loop diversity for uninterrupted
service protection in case of link failures. The SDH rings are commonly called self healing
rings, because traffic flowing in a certain path can
be automatically switch to an alternate path. Self healing rings works in two different type of way:
A- Unidirectional Self healing rings.
B- Bi-directional Self healing rings.
The concept of traffic in both type ring is different.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
20/29
For internal circulation of BSNL only
Features of SDH Rings There can be either two or four fibers running
between the nodes on a ring. The operating signals can travel either clockwise
only (USHR). The operating signals can travel in both directions
around the ring (BSHR). Protection switching can be performed either via a
line switched or a path switched scheme.
In BSNL only two fiber ring mechanism is beingadopted.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
21/29
For internal circulation of BSNL only
Concept Of Line Switched Protection
Uni-Directional Self Healing Ring
RX TX
TX RX
TX RX
RX TX
RX TX
TX RX
TX RX
RX TX
ADM A
ADM B
ADM C
ADM D
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
22/29
For internal circulation of BSNL only
Features of USHR This scheme offers less information regarding
operating System. In normal condition the traffic flows in clockwise
directions In one fiber.
In failure condition the traffic flows in counterclockwise direction path and is used as alternatepath for protection against ring or node failure.
The USHR mechanism itself does not remain awarewhich fiber is carrying traffic.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
23/29
For internal circulation of BSNL only
Features of USHR (contd.)
In case traffic is switched over to alternate
path the traffic is not returned on normalpath after restoration.
USHR is less informative but it protect
traffic positively. It offers cost effective solution for low level
of capacity network.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
24/29
For internal circulation of BSNL only
Concept of Speech in SDH Ring
Bi-Directional Self Healing Ring
RX TX
TX RX
TX RX
RX TX
Node 1
Node 2
Node 3
Node 4
RX TX
TX RX
TX RX
RX TX
1p
2p
3p
4p
5p
6p7p
8p
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
25/29
For internal circulation of BSNL only
Feature of BSHRBSHR is more informative.
The scheme requires a APS protocol to make itoperative. The traffic flows from node 1 to node 3 in clockwise
direction along links 1p and 2 p. But in return path the traffic flows in counterclockwise from node 3 to node1 along links 7p and 8p. Thus the information exchange between nodes 1 and3 does not tie up any of the primary channel bandwidthin the other half of the ring.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
26/29
For internal circulation of BSNL only
Ms Shared Protection Rings MS shared protection rings scheme is supported by
BSHR only. The ring protocol is essential for both two fiber ringas well as four Fiber ring.
In BSNL only two fiber rings are deployed. MS shared protection rings are characterized by
dividing the total payload per multiplex sectionequally into working and protection capacity.
For a two fiber STM-N ring, N/2 administrative unitgroups (AUGs) available for working and N/2
(AUGs) for protection.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
27/29
For internal circulation of BSNL only
Ms Shared Protection Rings (Contd.) The protection capacity is shared between multiple
multiplex sections.
The sharing of protection capacity may allow amultiplex section shared protection ring to carry moretraffic under normal conditions than other ring type.
The sum of the tributaries that transverse a spancannot exceed the maximum capacity of the particularspan.
In MS shared protection the service can be routed ineither one of the two directions, the long way aroundthe ring or the short way.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
28/29
For internal circulation of BSNL only
Ms Shared Protection Rings (Contd.)
For normal working shortest path is preferable. For failure condition ,the alternate path in used.
Maximum station may not be more than 16excluding regenerator.
SURVIVABILITY OF SDH N/W (Contd.)
7/25/2019 06-E3-E4 CFA-Overview of SDH.pdf
29/29
For internal circulation of BSNL only
Thanks