DELHI METRO RAIL CORPORATION LTD

Telecom Handbook

Networking

Maintenance Staff
8/19/2019
 Index

1. Introduction
2. Overview/Description/Definition
3. Purpose
4. Module/Sub Module and their functionality
5. Interconnectivity/Architecture
a. Power flow
b. Data flow
6. Software/Application/Configuration
7. Maintenance
a. Types of failures/Error
b. Troubleshooting
c. Module replacement procedure
d. Tools requirement/Safety Precaution
8. Health Check-up
a. Modules
b. Interface with other systems
c. Services
9. System Enhancements/Modifications
10. Do’s and Don’ts
11. Appendix
a. Version of Application
b. Specifications
 Introduction

A network is a group of interconnected devices. Networks may be classified according to a

wide variety of characteristics e.g,

i) Connection method

Networks can be classified according to the hardware and software technology that is used to
interconnect the individual devices in the network, such as Optical fiber, Ethernet, Wireless
LAN, etc.
Ethernet uses physical wiring to connect devices. Frequently deployed devices include hubs,
switches, bridges and/or routers. Wireless LAN technology is designed to connect devices
without wiring. These devices use radio waves or infrared signals as a transmission medium.

Wired technologies:

a. Twisted pair wire: This is the most widely used medium for telecommunication.
Twisted-pair wires are ordinary telephone wires which consist of two insulated
copper wires twisted into pairs and are used for both voice and data transmission.

b. Coaxial cable: These cables are widely used for cable television systems, office
buildings, and other worksites for local area networks. The cables consist of copper
or aluminum wire wrapped with insulating layer typically of a flexible material with a
high dielectric constant, all of which are surrounded by a conductive layer.

c. Fiber optics: These cables consist of one or more thin filaments of glass fiber
wrapped in a protective layer. It transmits light which can travel over long distance
and higher bandwidths. Fiber-optic cables are not affected by electromagnetic
radiation. Transmission speed could go up to as high as trillions of bits per second.
The speed of fiber optics is hundreds of times faster than coaxial cables and
thousands of times faster than twisted-pair wire.

ii) Scale

Networks are often classified as Local Area Network (LAN), Wide Area Network (WAN),
Metropolitan Area Network (MAN), Virtual Private Network (VPN), Campus Area Network
(CAN), Storage Area Network (SAN), etc. depending on their scale, scope and purpose.
LANs tend to be designed for internal use by an organization's internal systems and
employees in individual physical locations (such as a building), while WANs may connect
physically separate parts of an organization to each other and may include connections to
third parties.
 Overview
The Open Systems Interconnection model (OSI model) is a conceptual model that
characterizes and standardizes the communication functions of a telecommunication or
computing system without regard to its underlying internal structure and technology. Its goal
is the interoperability of diverse communication systems with standard communication
protocols. The model partitions a communication system into abstraction layers. The original
version of the model had seven layers. This model was developed by the International
Organization for Standardization (ISO) in 1984. Each layer is reasonably self-contained so
that the tasks assigned to each layer can be implemented independently. This enables the
solutions offered by one layer to be updated without adversely affecting the other layers.
The following list details the seven layers of the Open System Interconnection (OSI)
reference model:

 Layer 7—Application

 Layer 6—Presentation

 Layer 5—Session

 Layer 4—Transport

 Layer 3—Network

 Layer 2—Data link

 Layer 1—Physical

Characteristics of the OSI Layers

The seven layers of the OSI reference model can be divided into two categories: upper layers
and lower layers.

The upper layers of the OSI model deal with application issues and generally are implemented
only in software. The highest layer, the application layer, is closest to the end user. Both users
and application layer processes interact with software applications that contain a
communications component.

The lower layers of the OSI model handle data transport issues. The physical layer and the data
link layer are implemented in hardware and software. The lowest layer, the physical layer, is
closest to the physical network medium (the network cabling, for example) and is responsible for
actually placing information on the medium.

Application Specific Layers

 Layer 7—Application

 Layer 6—Presentation
  Layer 5—Session

Data Transport Specific Layers

 Layer 4—Transport

 Layer 3—Network

 Layer 2—Data link

 Layer 1—Physical

Protocols
The OSI model provides a conceptual framework for communication between computers, but
the model itself is not a method of communication. Actual communication is made possible by
using communication protocols. In the context of data networking, a protocol is a formal set of
rules and conventions that governs how computers exchange information over a network
medium. A protocol implements the functions of one or more of the OSI layers.

A wide variety of communication protocols exist. Some of these protocols include LAN
protocols, WAN protocols, network protocols, and routing protocols. LAN protocols operate at
the physical and data link layers of the OSI model and define communication over the various
LAN media. WAN protocols operate at the lowest three layers of the OSI model and define
communication over the various wide-area media. Routing protocols are network layer protocols
that are responsible for exchanging information between routers so that the routers can select
the proper path for network traffic. Finally, network protocols are the various upper-layer
protocols that exist in a given protocol suite.

OSI Model and Communication Between Systems

Information being transferred from a software application in one computer system to a software
application in another must pass through the OSI layers. For example, if a software application
in System A has information to transmit to a software application in System B, the application
program in System A will pass its information to the application layer (Layer 7) of System A. The
application layer then passes the information to the presentation layer (Layer 6), which relays
the data to the session layer (Layer 5), and so on down to the physical layer (Layer 1). At the
physical layer, the information is placed on the physical network medium and is sent across the
medium to System B. The physical layer of System B removes the information from the physical
medium, and then its physical layer passes the information up to the data link layer (Layer 2),
which passes it to the network layer (Layer 3), and so on, until it reaches the application layer
(Layer 7) of System B. Finally, the application layer of System B passes the information to the
recipient application program to complete the communication process.
Physical Layer: The physical layer is responsible for the transmission and reception of
unstructured raw data between a device and a physical transmission medium. It converts the
digital bits into electrical, radio, or optical signals.

Data Link Layer: The data link layer provides node-to-node data transfer—a link between two
directly connected nodes. It detects and possibly corrects errors that may occur in the physical
layer. It defines the protocol to establish and terminate a connection between two physically
connected devices. It also defines the protocol for flow control between them.
IEEE 802 divides the data link layer into two sublayers:

 Medium access control (MAC) layer – responsible for controlling how devices in a network
gain access to a medium and permission to transmit data.
 Logical link control (LLC) layer – responsible for identifying and encapsulating network layer
protocols, and controls error checking and frame synchronization.

Network Layer: The network layer provides the functional and procedural means of transferring
variable length data sequences (called packets) from one node to another connected in
"different networks". A network is a medium to which many nodes can be connected, on which
every node has an address and which permits nodes connected to it to transfer messages to
other nodes connected to it by merely providing the content of a message and the address of
the destination node and letting the network find the way to deliver the message to the
destination node, possibly routing it through intermediate nodes. If the message is too large to
be transmitted from one node to another on the data link layer between those nodes, the
network may implement message delivery by splitting the message into several fragments at
one node, sending the fragments independently, and reassembling the fragments at another
node. It may, but does not need to, report delivery errors.

Transport Layer: The transport layer provides the functional and procedural means of
transferring variable-length data sequences from a source to a destination host, while
maintaining the quality of service functions.
The transport layer controls the reliability of a given link through flow
control, segmentation/desegmentation, and error control.

Session Layer: The session layer controls the dialogues (connections) between computers. It
establishes, manages and terminates the connections between the local and remote
application. It provides for full-duplex, half-duplex, or simplex operation, and establishes
procedures for checkpointing, suspending, restarting, and terminating a session.

Presentation Layer: The presentation layer establishes context between application-layer

entities, in which the application-layer entities may use different syntax and semantics if the
presentation service provides a mapping between them. If a mapping is available, presentation
protocol data units are encapsulated into session protocol data units and passed down
the protocol stack.

Application Layer: The application layer is the OSI layer closest to the end user, which means
both the OSI application layer and the user interact directly with the software application. This
layer interacts with software applications that implement a communicating component.

IP Addressing Scheme:

The purpose of IP addresses is to enable communication between networks. An Internet

Protocol version 4 (IPv4) address is a 32-bit number represented as four octets. This is usually
shown in dotted decimal notation. This notation uses four decimal numbers ranging from 0 -
255.
Example: 192.5.5.1
An IP address is used to identify networks and hosts. The network id and the host id bits
depend on the class of address.
There are 5 classes of IP address but only three are available for public use.

 Class A
 Class B
 Class C
 Class D
 Class E

Class A, B and C are used publicly while D is reserved for multicasting and E for experimental
purposes.

Class A
First octet range: 1 to 126

Example: 10.0.0.0

Default subnet mask: 255.0.0.0

The first octet is used for network identification; the remaining three octets are used for host id.
Only 126 class A networks exist but each can have over 16m hosts.

Note: The class A IP Address of 127.0.0.1 is reserved and is commonly known as the loopback
address. Typing ping 127.0.0.1 at your workstation's command prompt will perform the loopback
test to ensure that the workstation's network card is functioning properly.

Class B

First octet range: 128 - 191

Example: 172.16.0.0

Default subnet mask: 255.255.0.0

The first two octets are used for network id and the remaining two are used for host id. There
are over 65000 class B networks each with over 65000 hosts.

Class C

First octet range: 192 - 223

Example: 192.130.5.40
Default subnet mask: 255.255.255.0

The first three octets are used for the network id and the last remaining octet is used for the host
id. There are over 16m class C networks each network can have a maximum of 254 hosts.

The network id will have a value in the network octets and all host octets will be set to 0, eg:
189.154.0.0 indicates this is class B network 189.154.

Subnet Mask: Subnet masks can be used to identify how many bits belong to the network. Often
networks are segmented to create independent networks by borrowing bits from the host octets.
If the whole octet represents the network the subnet will be 255. If some bits are borrowed the
binary value of the borrowed bits will be shown in the subnet, eg: 255.255.240.0 will indicate
that four bits have been borrowed.

Types of Network Topologies:

Any computer network design can be said to have evolved from one of three basic topologies.
These three topologies can also be combined in a variety of ways to form more complex hybrid
topologies. These three topologies are:
 Bus
 Star
 Ring

Bus

A bus topology is commonly referred to as a "linear bus" because all of the nodes are physically
connected in a straight line. A bus topology has a single backbone cable to which computers
and other devices are connected. This backbone is also known as a segment or a trunk.

Star
In the star topology, cables from each computer are connected to a central device known as a
hub. Signals are transmitted from the sending computer through the hub to all computers on the
network. This topology has its origins in the early days of computing when terminals were
connected to a central mainframe computer.

The star network topology has the advantage of centralising resources and management,
however, more cable is required than for other topologies. The star topology also has a central
point of failure, that is, if the hub at the centre of the topology fails then the whole network will be
down.

If one of the computers (or the cable that connects it to the hub) fails on a star network, only the
failed computer will not be able to send or receive network data. The rest of the network will
continue to function normally.

Ring

The picture shown is a classical ring topology and consists of a physical ring and a logical ring.
Each computer is linked to two others to form a closed loop. Each node in this ring will act as a
repeater by regenerating and cleaning up a signal before passing it to the next node.

This is most widely used topology in DMRC network.

 Purpose

A computer network is defined as interconnected collection of autonomous computers.

Computer are said to be interconnected, if they able to exchange information. Connection is
physically established through cables, lasers, microwaves, fiber optics and communication
satellite.

The following are the objectives of the computer networks.

1. Resource sharing is the main objective of the computer network. The goal is to provide all
the program, data and hardware availability to everyone on the network without regard to the
physical location of the resource and the users.

2. The second objective is to provide the high Reliability. It is achieved by replicating the files
on two or more machines, so in case of unavailability (due to fail of hardware) the other copies
can be used.

3. Computer organization has helped organization in saving money. This is due to the fact that
the small computer has much better price to the performance ratio comparison than the large
computer like mainframe. Mainframe computer are approximately ten times faster that the
microcomputers, but they cost thousands times more. As a result of this imbalance, organization
has preferred to install interconnected microcomputer connected to the mainframe computer.

4. Computer network have provided means to increase system performance as the work load
increases (load balancing). In the days of mainframe when the system was full it was to
replace with the other large mainframe computer, usually at an expensive rate not convenient
for user.

5. Computer network help people who live or work apart to report together. So, when one user
prepared some documentation, he can make the document online enabling other to read and
convey their opinions. Thus computer network is a powerful communication medium.

6. Only authorized user can access resource in a computer network. Users are authenticated by
their user name and password. Hence it is not possible to access the data without proper
account. This increases security.
 Module/Sub Module and their functionality
Hubs

OSI Model: Layer 1 Device

Protocol Data Unit(PDU): Bits

Hubs operate at the Physical Layer of the OSI model and can be generally divided into two
types, active and passive.

Passive hubs do not amplify the electrical signal of incoming packets before broadcasting them
out to the network, whereas, active hubs retime and regenerate signals in a similar way to a
repeater. A very important fact about hubs is that they allow users to share an Ethernet LAN.

Switches

OSI Model: Layer 2 Device

Protocol Data Unit(PDU): Frames

A switch is an OSI layer 2 device that allows network microsegmentation. LANs can be
segmented to limit network traffic and therefore to reduce collisions. Traffic flows within a
segment but only leaves that segment if it is really necessary. A segment can be a number of
computers such as a department or it may be a single computer.

A switch works by examining the MAC address (layer 2 address) of incoming frames. Switches
learn MAC addresses as traffic is generated, a switching table built, very quickly the switch has
enough information to operate effectively. A switch examines MAC addresses of frames. If the
frame is local ie: the MAC address on the same network segment as the incoming port of the
switch then the frame is not forwarded across the bridge. If the frame is not local ie: with a MAC
address not on the incoming port of the switch then it is forwarded to the appropriate network
segment. All the decision-making is carried out by the switching circuits based on MAC
addresses.

A switch cannot be used to connect different types of network, that job falls to the router.

Managed and Unmanaged Switch

A managed switch allows you have better control of your network and all the traffic moving
through it. An unmanaged switch allows Ethernet devices to communicate with one another
automatically using auto-negotiation to determine parameters such as the data rate and whether
to use half-duplex or full-duplex mode.

A managed switch lets you adjust each port on the switch to any setting you desire, allowing
you to monitor and configure your network in many different ways. It also provides greater
control over how data travels over the network and who has access to it. Managed switches
generally offer SNMP (Simple Network Management Protocol), which allows you to monitor the
status of connections and gives you statistics like traffic throughput, network errors and port
status.

Features available on managed switches may vary between manufacturers and models, but
often include Spanning Tree Protocol (STP) support, ability to implement quality of service
(QoS), support for virtual LANs (VLANs), bandwidth rate limiting and port mirroring. These
switches usually have a remotely accessible console (command line or Web interface) to allow
administrators to make changes or adjustments without being in the same physical location.
Managed switches are also quite a bit more expensive. Setting them up may take a little longer
as compared to unmanaged switches, which are generally plug and play.

Routers

OSI Model: Layer 3 Device

Protocol Data Unit(PDU): Packets

Where a network consists of several segments with differing protocols and architectures a
bridge might be inadequate. The network needs a device that not only knows the address of
each segment, but can also determine the best path for sending data and filtering broadcast
traffic to the local segment. Such a device is called a router.

Routers work at the network layer of the OSI reference model. This means they can switch and
route packets across multiple networks. This is achieved by exchanging protocol specific
information between separate networks. Routers can read complex network addressing
information in the packet and, because they function at a higher layer in the OSI reference
model than bridges, they have access to additional information. Routers can provide the filtering
and isolating of traffic and the connection of network segments.

Routers are used in networks because they provide better traffic management. Routers can
share routing information with one another and use this information to bypass slow or broken
connections.

Routers require specific addresses. They understand only the network numbers that allow them
to communicate with other routers. Routers build up a database of available routes and
information about the routes. This is called a routing table.
Routers do not look at the destination node address; they look only at the network address.
Routers will pass information only if the network address is known. This ability to control the
data passing through the router reduces the amount of traffic between networks and allows
routers to use these links more efficiently.

The two major types of routes are defined in a router:

 Static Static routes require an administrator to manually set up and configure the routing
table and to specify each route.
 Dynamic Dynamic routes are designed to discover routes automatically and therefore
require a minimal amount of setting up and configuration. E.g, OSPF,RIP etc.

Media Convertors

They are used to convert media from one format into a different one such as Ethernet to Optical,
Ethernet to Serial, and Ethernet to E1 and vice versa.
 System Architecture

Power flow

System
ACDB RACK Equipment
Power
From UPS
strip
 Data Flow SDH Backbone

Switch Router SDH

Server/Workstation

Switch Router SDH

Local Server/Equipment
 DMRC PHASE II SWAN DATA CONNECTIVITY

J2320
OCC LAN
ES 425-24T Site F
Switches

J2320
M10i
OCC SDH Backbone
ES 425-24T
Site E
J2320

ES 425-24T
J2320
Site A
J2320 J2320
ES 425-24T
Site D
ES 425-24T
ES 425-24T
Site B Site C

Switches and routers used in SWAN network in phase 2:

Router at OCC: JUNIPER M10i (1 router at each OCC )

Router at stations: JUNIPER J2320 (2 routers at each station)

Switches at OCC: Nortel Baystack 5520 with 24 ports (2 SWITCHES)

Switches at stations: Nortel Baystack ES 425-24T (2 Switches at each station)

 Ring architecture of SWAN network in DMRC:

S.No. Line Ring Name

1 1 MPK-DSG
2 2 GTBR-JGPI
3 2 UDB-JB
4 2 INA-GNPK
5 2 HKS-QM
6 2 CHTP-AJG
7 2 GE-HCC
8 3 NCC-NSET
9 3 NSST-MVE
10 3 MVP1-YBS
11 3 DSTO-DSET
12 4 KSHI-VSLI
13 4 LN-AVIT
14 5 ILOK-PBGE
15 5 SHPV-PVW
16 5 PAGI-NNOI
17 5 NRSN-MUDKD
18 6 CTST-LJPT
19 6 MLCD-NP
20 6 KJMD-STVR
21 6 SVD-BAPU
 DMRC PHASE I DATA CONNECTIVITY

OCC SHPK for Line-1 & Line-2 Phase-1 stations:

Hp A5500 series switch Hp A6608 JC177B

JG312A with 48 ports router
with 4 WAN
channel
cards(8E1/75) along
Stacking cable
with 17 H3C Balun SDH BACKBONE
Hp A5500 series switch Box(G.703 Balun)
JG312A with 48 ports

Station A Station B

Hp a-MSR Hp a-MSR 30- Hp a-MSR Hp a-MSR

30-10 router 10 router 30-10 router 30-10 router

Switch Switch Switch Switch

HP 2620 24 PORTS SWITCH HP 2620 24 PORT SWITCH

 Ring architecture for stations at Line-1 & Line-2 for Phase-1:

S.no. Line Ring Name

1 1 SHD-SLAP
2 1 SHPK-TZI
3 1 PBGH-ILOK
4 1 KN-KE
5 1 PTP-RI
6 2 KPD-CL
7 2 KGM-NDI
8 2 RCK-CTST

Ring architecture for stations at Line-3 phase-1 :

S.no Line Ring Name

1 3 IDPT-BRKR
2 3 RCK-KB
3 3 RP-KNR
4 3 MN-TG
5 3 SN-JPW
6 3 UNE-DM
7 3 DW-DSTN
8 3 DSW-DSN
 Software/Application/Configuration

Router Configuration

a. Login switch by console port using laptop.

b. Enter username and password.
c. Restore the backup file of router.
d. Reboot the router.

The sample configuration file of Juniper router at phase-2 stations is as below:

## Last commit: 2014-06-20 09:33:47 IST by tvsnet

version 10.2R3.10;

system {

host-name MNPK_R2;

time-zone Asia/Calcutta;

root-authentication {

encrypted-password "$1$nCs2wdev$YBEIe8jh1Hra/U3tu8p3U."; ## SECRET-DATA

login {

user tvsnet {

uid 2000;

class super-user;

authentication {

encrypted-password "$1$rCLuD8PH$FAG.5El0lE9hV1vcL/HeN."; ## SECRET-DATA

services {

ssh;

telnet;

web-management {
 http {

interface ge-0/0/0.0;

syslog {

user * {

any emergency;

file messages {

any any;

authorization info;

file interactive-commands {

interactive-commands any;

license {

autoupdate {

url https://ae1.juniper.net/junos/key_retrieval;

ntp {

server 10.126.100.118; Master Clock IP Address

interfaces {

ge-0/0/0 {

unit 0 {
 family inet {

address 10.126.4.3/24 {

vrrp-group 1 {

virtual-address 10.126.4.1;

priority 150;

accept-data;

authentication-type md5;

authentication-key "$9$WQVL-Vs24ZDiY2"; ## SECRET-DATA

ce1-2/0/0 {

e1-options {

framing g704;

no-partition interface-type e1;

e1-2/0/0 {

description link_to_SHPKOCC;

encapsulation ppp;

unit 0 {

family inet {

address 10.127.1.2/30;

ce1-2/0/1 {
 e1-options {

framing g704;

no-partition interface-type e1;

e1-2/0/1 {

description link_to_JLML;

encapsulation ppp;

unit 0 {

family inet {

address 10.127.1.13/30;

lo0 {

unit 0 {

family inet {

address 127.0.0.1/32;

snmp {

description "Juniper router 1";

location Mansarovar;

contact dmrc;

engine-id {

local 4;

}
 community public {

authorization read-write;

trap-group nms {

categories {

chassis;

link;

routing;

vrrp-events;

targets {

10.126.100.7;

protocols {

igmp {

interface all {

version 2;

ospf {

area 0.0.0.0 {

interface ge-0/0/0.0;

interface e1-2/0/0.0;

interface e1-2/0/1.0;

pim {
 rp {

static {

address 10.126.1.1 {

group-ranges {

239.0.0.0/24;

interface all {

mode sparse;

version 2;

security {

zones {

security-zone trust {

host-inbound-traffic {

system-services {

all;

protocols {

all;

interfaces {

ge-0/0/0.0 {

host-inbound-traffic {
 system-services {

all;

protocols {

all;

e1-2/0/0.0 {

host-inbound-traffic {

system-services {

all;

protocols {

all;

e1-2/0/1.0 {

host-inbound-traffic {

system-services {

all;

protocols {

all;

}
 }

policies {

from-zone trust to-zone trust {

policy accept-all {

match {

source-address any;

destination-address any;

application any;

then {

permit;

alg {

ftp disable;

h323 disable;

msrpc disable;

sccp disable;

sip disable;

flow {

tcp-session {

no-syn-check;

no-sequence-check;

}
 Maintenance

a. Types of failures/error

Downtime caused by network problems has a major impact on systems. Tackle these leading
causes of network problems to minimize telecom failures.

i) Misconfiguration: Misconfiguration is the cause of as many as 80% of unplanned

outages. Test all configurations in a lab environment before making changes on
live devices.
ii) Old equipment: Every obsolete, unsupported device is a potential threat to
network’s functioning. Be proactive in planning upgrades and replacing out-of-
date equipment.
iii) Human Error: Perhaps the leading causes of outage are unintentional mistakes.
Along with configuration errors, people make mistakes that can be as simple as
pulling the wrong plug or not knowing the proper procedure. Avoid these errors
through proper staff training and proper documentation, including labels on all
devices.
iv) Hardware failures: Any device can fail; make sure you perform maintenance and
apply patches as needed to keep devices up to date and reduce the risk. You
can also reduce the impact of any device failure by building in redundancy to
prevent a single point of failure from disrupting the whole network.
v) Power failures: Have backup power supplies to prevent a power outage from
shutting you down. Connect redundant devices to different power circuits to
ensure a single circuit outage doesn’t shut down a service entirely.

b. Troubleshooting

On basis of the above mentioned failures following is the troubleshooting procedure:

i) Misconfiguration: Keep a tested copy of switch or router configuration in each

section. Compare the running configuration with the saved one. If any change
has taken place, try to revert to original and check whether system starts working
normal or not.
ii) Old equipment: Arrange spare equipment for each section. Replace the
equipment with new and make the proper configuration changes. System will
start working normal.
iii) Human Error: Prepare Switch/Router port details. Keep a copy either in TER or
stick on the rack. Try to verify twice before unplugging/plugging a cable to
switch/router. Labeling should be proper and make a routine to check whether
any wrong change have been taken place or not. If so, change the label.
iv) Hardware failures: Arrange a spare equipment and after restoring the backup
configuration. Connect all cables.
There might be problems in connecting cables. Test with LAN tester/E1 tester or
OTDR and if there is a problem, replace with another cable/patch cord.
There are also some instances on which it is found that a physical port got
hanged or a switch/router struck in hanged state. Try to unplug and then plug
cable in case of earlier one and reboot the switch/router in case of later.
v) Power failure: In equipments which are having replaceable power supply unit,
arrange few spare units and replace on the occurrence of failure. On the rest
equipments, either there is some problem in power cord or MCB. Replace the
faulty parts and system will start working normal.
Module Replacement Procedure

Replacing a complete Switch or Router

i) Arrange a spare switch/router.

ii) Login the new switch/router with laptop.
iii) If new switch/router is of same model as the faulty one, restore the backup
configuration file else try to make changes in switch/router after seeing the older
switch/router configuration file.
iv) Reboot the switch/router.
v) Install in rack.
vi) Connect the cables properly.

Replace a Modular Switch/Router

i) Arrange modular components of those switches/router.

ii) Replace the faulty module.
iii) Reboot the switch/router.
iv) Connect the cables properly.

Tools Requirements

i) Screw Driver Set

ii) Aligner set
iii) Crimping tool
iv) LAN tester, E1 tester and Power/Source meter.
 Health checkups
A) Modules

A switch/router should be regularly checked for its health status and proper functioning. There
are certain commands through which the current system information, alarm status, physical
environment status etc can be checked. Commands are different for different models.

Example:

show system [ information | power-supply | temperature | fans ]

This command displays global system information and operational parameters for the switch.

information
Shows global system information and operational parameters for the switch.

power-supply
Shows chassis power supply and settings.

temperature
Shows system temperature and settings.

fans
Shows system fan status.

Command list for a particular model can be accessed by typing “help” in CLI (Command Line
Interface).
b).Interface with other systems:

The switches installed at OCC acts as an interface of communication for the following systems:

1). ATS Servers:

The ATS servers communicate with the PIDS-PAS servers at OCC through the telecom core
switch installed at OCC.

2).Master clock

3).NP-SCADA

Health status of these interfaces should be checked by PING command and thus ensuring the
proper connectivity.