ccna chapter 10 by jetarvind kumar madhukar

Release 16/07/2009 Jetking Infotrain Ltd.

ISDN Configuration

Chapter 10

Release 16/07/2009Jetking Infotrain Ltd.

Chapter Objectives

Explain ISDN features Explain ISDN devices Explain ISDN connections Configure BRI Configure PRI Verify ISDN Connections


Recall

WAN is a network that spans a large geographical area

Data-Link layer protocols are commonly called the data link protocols, which communicate between two devices

PAP is a insecure protocol because the username and password is sent in plain text

Use debug ppp authentication to troubleshoot PPP Using CHAP protocol the server sends challenge

messages to the node. The node calculates and sends the results back to the server


ISDN Features

ISDN provides Wide Area Network (WAN) services in incremental values of 64 kbps

The features of ISDN are: Speed Multiple Device Support Inexpensive


ISDN Channels and Services

ISDN network transmits information through the three logical digital communication channels such as Bearer (B) channel, Data (D) channel and Hybrid (H) channel

H channel can be implemented as H0, H10, H11, H12

ISDN supports two types of connections such as the Basic Rate Interface (BRI) and Primary Rate Interface (PRI)


ISDN Devices

The ISDN devices are given as follows: Network Termination Device 1 (NT1) Network Termination Device 2 (NT2) ISDN Router Terminal Equipment 1 (TE1) Terminal Equipment 2 (TE2) Terminal Adapter (TA)


ISDN Connections

ISDN is a channelized service A channelized service splits a wire into many logical

channels or time slots Some of the common terms that are used in

channelized connections are: Digital Signal 0 (DS0) Digital Signal 1 (DS1) T1 E1


ISDN Devices and Reference Points


ISDN Protocols The following are ISDN protocols dealing with certain

issues: Protocols with E as the beginning letter deal with using

ISDN on the existing telephone lines Protocols with I as the beginning letter deal with ISDN

concepts, aspects and services Protocols with Q as the beginning letter deal with

switching and signaling. These protocols allow you to connect to the ISDN and troubleshoot the network. The Q protocols include the following: Q.921 Q.931


Switch Types and Connections - I

Switch Type Connection Type

basic-5ess BRI

basic-dms100 BRI

basic-ni1 BRI

basic-ni2 BRI

basic-1tr6 BRI

basic-net3 BRI

basic-nwnet3 BRI

basic-nznet3 BRI

basic-ts013 BRI


Switch Types and Connections - II

ntt BRI

vn2 BRI

vn3 BRI

vn4 BRI

vn5 BRI

pri-4ess PRI

pri-5ess PRI

pri-dms100 PRI

pri-nt PRI

pri-net5 PRI


Selecting Router ISDN Interface To select a Cisco router with the correct ISDN

interface: Check whether the router supports ISDN BRI Identify the NT1 provider. NT1 ends the local loop

to the Central Office (CO) of the service provider Check whether NT1 is Customer Premises

Equipment (CPE)


ISDN Call Setup Procedure

To set up an ISDN call between the router and the ISDN switch, the D channel is used whereas, between the switches within the service provider’s network, Signaling System 7 (SS7) is used

By default, the D channel is always enabled During the ISDN call, the calling host sends a call

setup request Before the actual connection is established, many

different messages are sent across such as progress messages and alert messages


Configuring BRI

You can configure the BRI for the router after connecting the ISDN equipment

The generic steps to configure BRI are: Setting an user name and password Setting the switch type Configuring ISDN interface on a router Setting the Service Profile Identifier (SPID)


Setting the SPID

Service Profile IDentifier (SPID) is a set of numbers for BRI connections that have a National ISDN-1 or Nortel DMS-100 switch

The SPID consists of the ten-digit telephone number for the connection and extra identification digits

The SPIDs are provided along with the switch carrier


Configuring PRI - I You need to configure additional parameters for PRI on

your router After setting the switch type, you need to configure the

T1/E1 controller card and the serial interface of the controller card

The different configuration settings for the controller card include: Framing Line code Clock source Timeslots


Configuring PRI - II

The generic steps to configure PRI are: Setting the ISDN switch type with which the router

will communicate Selecting the controller and specifying the type

(T1/E1), framing type and line coding for the provider

Setting the port to function as PRI and specifying the PRI slot for T1 or E1 and the speed


Verifying ISDN Connections

After configuring the interfaces, you need to verify that they have been configured properly

You can verify the ISDN connections using two commands show interface command show isdn status command


ISDN Verification Commands - I

Command Description

ping and telnet Enables you to ping or telnet the remote router when the link is established without considering the interesting traffic list

show dialer Provides dialer information that includes status of the link, idle time, length of the call, router to which the interface is connected

show isdn active Displays the phone number and whether the call is active


ISDN Verification Commands - IIshow isdn status Displays the detailed status of the ISDN

interfaces

show ip route Displays all the routes of the router

debug isdn q921 Enables you to view layer 2 information

debug isdn q931 Enables you to view layer 3 information

debug dialer Provides the call setup and disabled activities

isdn disconnect interface bri 0 Enables you to clear the interface and disconnect the connection


Dial on Demand Routing

Cisco provides Dial on Demand Routing (DDR) feature that allows the Cisco router to dial an ISDN when it receives an interesting traffic

The interesting traffic is referred as IP traffic fulfilling specific criteria such as particular protocol and highly secured destination address

If a traffic using particular criterion is set as interesting traffic, the traffic is given the highest priority during the transmission


Making a phone connection - I To make a phone connection, the DDR goes through the

following process: When a packet is received, the router checks the

routing table to locate the destination The router determines if the packet is interesting. The router establishes DDR connection by dialing the

ISDN. When the received packet is interesting and the DDR is not active, the router makes a phone call to establish connection. If the received packet is not interesting and the DDR is not active, the router drops the packet. However, the router transmits all the packets if the DDR already active


Making a phone connection - II

Once the connection is established, the router transmits the packets from the DDR interface

The router terminates the connection if no packets are to be transmitted or the connection remains idle for certain period


DDR Configuration - I

You can allow the Cisco router to perform the DDR process by configuring it

DDR can be used in the following situations: The telecommuters need to connect to the

company network periodically There are offices that need to send transactions

or requests to the main computer at the central office

The users need to retrieve the e-mail from the ISP


DDR Configuration - II

The generic steps to configure legacy DDR are: Configuring static routes that are the routes for

remote networks Specifying which traffic is interesting Activating dialer list that contains the information

about the traffic that can generate calls Configuring a dialer map that informs the router to

make a call using legacy DDR


Configuring Static Routes

The DDR feature of Cisco allows you to prevent unwanted traffic from making phone calls and keeping the line busy

configuring static routes helps in avoiding other traffic to trigger calls

The ip route command enables you to define the static route. The syntax of this command is:

ip route network_IP_address_# subnet_mask remote_router’s_IP_address|router_interface [administrative_distance]


Specifying Interesting Traffic

Access Lists (ACLs) allows you to specify the interesting traffic on the router

Using the dialer-list command, you can allow only the IP traffic to establish connection

The dialer-list command enables you to specify which traffic is interesting. The syntax of this command is:

dialer-list [list_#] protocol [protocol_name] permit|deny access-list [ACL_#]


Activating Dialer List

You need to activate the dialer list on the DDR interface after the list is created

It is necessary to activate the list because the list is not an ACL and it only specifies which traffic is interesting traffic by referring an ACL

To activate the dialer list, you should use the dialer-group command. The syntax of this command is given as follows:

dialer-group dialer_list_#


Configuring Dialer Maps

Once you finish specifying the interesting traffic and activating the dialer list on the DDR interface, you can specify dialer information to the router

The dialer map command gives dialer information for the router to make phone calls. The syntax of the command is:

dialer map protocol_name destination_router_address name [remote_router] speed [56|64] [broadcast] [destination_phone_number]


Dialer Profiles

With the help of dialer profiles, the following tasks can be performed: Configuring B channels with different IP subnets Using encapsulation on the B channel Setting DDR parameters for the B channels Eliminating the garbage of ISDN B channels by

allowing ISDN BRI interfaces to associate with multiple dialer pools


Configuring Dialer Profiles

You can configure many dialer interfaces on the router wherein each interface will contain complete information about the possible destinations

The initial steps in configuring dialer profiles include configuring static routes and dialer list similar to legacy DDR

you need to configure the dialer and the physical interfaces then


Verifying DDR Configuration

After configuring the interfaces, you need to verify that they have been configured properly

To verify the DDR configuration, there are three commands: show dialer interface show isdn active show isdn status


Troubleshooting ISDN DDR

The show and debug commands enable you to verify and troubleshoot the DDR connections show command - You can use the show dialer

command to view the DDR interfaces that made the phone calls

debug command - You can use the debug dialer command to view the DDR process to enable or disable the connection


Case Study

The Blue Diamond Steel company opened a new branch at Hyderabad. The organization uses regular telephone line for data transmission. All the departments of the Hyderabad branch send the details of their daily transactions to the Gujarat branch. The files that contain the transaction details are very large in size.


Problem

The data transmission is slow which incurs a lot of expense on each call


Suggested Solution

Implement Cisco routers in the network and configure ISDN on each router. The Cisco routers provide Dial on Demand Routing (DDR) feature, which allows the router to call the ISDN when it receives important traffic. Setup the PRI service for data transmission, which provides 23 B channels and 1 D channel


Summary - I

The Integrated Services Digital Network (ISDN) is a set of international standards that define data transmission across digital circuits

ISDN provides Wide Area Network (WAN) services in incremental values of 64 kbps

ISDN requires only 2 seconds to complete a call as compared to analog signals that require 30 seconds

Network Termination Device 1 (NT1) provides an interface between the ISDN BRI line and other devices


Summary - II

Network Termination Device 2 (NT2) communicates with the ISDN protocols

ISDN Router enables multiple computers on a LAN to share a single ISDN BRI connection

Terminal Adapter (TA) converts some other form of signaling to ISDN to enable non-ISDN devices, such as the TE2 to work the 2-wire ISDN network

The U point is a 2-wire interface for connecting to the (NT1)

The division of the wire into logical time slots is termed as Time Division Multiplexing (TDM)


Summary - III

The S reference point provides a 4-wire interface between the NT1 and the ISDN networking equipment such as an ISDN adapter or a router

Basic Rate Interface (BRI) consists of two B channels and one D channel

Primary Rate Interface (PRI) consists of multiple B and D channels

The ISDN interfaces can be configured using the interface command

The Internet Service Provider (ISP) provides the switch type for the ISDN connection


Summary - IV

Service Profile IDentifier (SPID) is a set of numbers for BRI connections that have a National ISDN-1 or Nortel DMS-100 switch

The show interface command enables you to view the ISDN interface configuration

The show isdn status command enables you to view the detailed status of the ISDN interfaces

ccna chapter 10 by jetarvind kumar madhukar

Education

isdn bri

isdn connections isdn

isdn features isdn

isdn protocols

isdn devices

features of isdn

isdn channels

isdn concepts