Voice over IP/Frame Relay Lab Scenarios

Date of Issue: 02-01-2000 Voice over IP/Frame Relay Lab Scenarios by Chris Ackerman Lab Scenario 1 - Voice over IP Objective Configuration of Router A Configuration of Router B Expla

Date of Issue: 02-01-2000

Voice over IP/Frame Relay Lab Scenarios

by Chris Ackerman

Lab Scenario 1 - Voice over IP

Objective

Configuration of Router A

Configuration of Router B

Explanation of Router Commands

Lab Scenario 2 - Voice over Frame-Relay

Objective

Configuration of Router A

Configuration of Router B

Explanation of Router Commands

Lab Scenario 1 - Voice over IP

Objective

Your organization wants to call from one location to another via your private leased line, which is passing only IP traffic Because of this, you decide that a VoIP solution is the best way to do go about providing communication between the two offices

As Network Administrator, you note that each site is using a Cisco 2610 You also find that there is room to put an FXS port on each of them To make calling easy for the users, create a simple dialing plan For the phone attached to Router A, dial 1001, and for the phone attached to Router B, dial 1002

Figure 1 Voice Over IP Lab

Note that the WAN must be able to support traffic from the two Ethernet segments and provide quality voice service

Configuration of Router A

Building configuration

Current configuration:

!

version 11.3

service timestamps debug uptime

service timestamps log uptime

no service password-encryption

!

hostname Router_A

enable secret 5 $1$IM1E$54nbR7ceGJQHXdqCBMoTU

!

ip subnet-zero

no ip domain-lookup

!

dial-peer voice 101 voip

destination-pattern 1002

ip precedence 5

session target ipv4:172.16.16.2

!

dial-peer voice 201 pots

destination-pattern 1001

port 1/0/0

!

voice-port 1/0/0

vad

!

voice-port 1/0/1

vad

!

interface Ethernet0/0

ip address 172.16.17.1 255.255.255.0

!

interface Serial0/0

ip address 172.16.16.1 255.255.255.252

!

ip classless

!

router eigrp 1

network 172.16.0.0

!

line con 0

transport input none

line aux 0

line vty 0 4

password cisco

login

!

end

Configuration of Router B

Building configuration

Current configuration:

!

version 11.3

service timestamps debug uptime

service timestamps log uptime

no service password-encryption

!

hostname Router_B

enable secret 5 $1$IM1E$54nbR7ceGJQHXdqCBMoTU

!

ip subnet-zero

no ip domain-lookup

!

dial-peer voice 101 voip

destination-pattern 1001

ip precedence 5

session target ipv4:172.16.16.1

!

dial-peer voice 201 pots

destination-pattern 1002

port 1/0/0

!

voice-port 1/0/0

timeouts call-disconnect 0

!

voice-port 1/0/1

timeouts call-disconnect 0

!

interface Ethernet0/0

ip address 172.16.18.1 255.255.255.0

!

interface Serial0/0

ip address 172.16.16.2 255.255.255.252

!

ip classless

!

router eigrp 1

network 172.16.0.0

!

line con 0

transport input none

line aux 0

line vty 0 4

password cisco

login

!

end

Explanation of Router Commands

Since both routers have similar configurations we will only look at Router A

Dial Peer statements are used to configure phone call routing There are two basic dial peer statements: 1) ones that point to local voice ports, Dial-peer Pots, and 2) the ones that point to a remote system, Dial-peer VoIP

Each peer can be configured to respond in a unique way For example, the dial-peer statement can place priority on the call packets This can be configured by placing a higher IP precedence on the packets destined for the dial-peer VoIP remote IP address VoIP packets with a precedence of 5 are given higher priority than packets from the Ethernet segments

dial-peer voice 101 voip

destination-pattern 1002

ip precedence 5

session target ipv4:172.16.16.2

dial-peer voice 201 pots

destination-pattern 1001

port 1/0/0

A voice port is a special type of router interface that accepts voice data from outside sources Voice ports can be configured to take advantage of Voice Activated Detection (VAD)

voice-port 1/0/0

vad

!

voice-port 1/0/1

vad

Lab Scenario 2 - Voice over Frame-Relay

Objective

As the CIO, you want to reduce the costs of your long distance phone bills After doing some research you find that

the bulk of the long distance calls are made to the remote office If these costs could be curtailed, the phone bill would

be reduced by 60%

Already existing is a Frame-Relay network between the two sites with a CIR of 768 Kbps Although the company needs this network to do business, you find that the traffic between the sites is a bit lower than the CIR even at peak You have heard that Voice over IP is not as efficient as Voice over a Layer 2 protocol, so you decide to take

advantage of your already existing Frame-Relay network to transport voice

Figure 1 Voice Over Frame-Relay Setup

For employee satisfaction, you have decided that you want no calls to be blocked Call traffic analysis has revealed that there are typically no more than four simultaneous calls between the offices

Build a Frame-Relay network using Cisco 3810 multi-service routers at each site You will need to connect the routes

to the local PBXs and direct traffic destined for the remote site to the 3810s The 3810 routers will receive voice from the PBX, encode it using G.729a, and send to the remote 3810

A caller will dial 8 to access the 3810s before dialing the four digit extension of the remote office called party Any four-digit number starting with 4 will be sent to the remote site and any four-digit number starting with 2 will be sent to corporate

Each of the 3810 routers has an Ethernet interface running IP IP traffic between the two routers will need to be transported as well

Configuration of Router A

!

Version 11.3

No service pad

No service password-encryption

!

hostname Router_A

!

!

network-clock base-rate 64k

no ip domain-lookup

!

!

controller T1 0

framing esf

linecode b8zs

channel-group 0 timeslots 1-24 speed 64

!

controller T1 1

framing esf

clock source internal

linecode b8zs

mode cas

voice-group 1 timeslots 1-4 type e&m-wink-start

!

interface Ethernet0

ip address 172.16.17.1 255.255.255.0

!

interface Serial0

no ip address

shutdown

!

interface Serial1

no ip address

shutdown

!

interface Serial2

no ip address

encapsulation frame-relay

frame-relay traffic-shaping

hold-queue 1024 out

!

interface Serial2.1 point-to-point

ip address 172.16.16.1 255.255.255.252

frame-relay interface-dlci 102 voice-encap 80 class-FR1

!

router eigrp 100

network 172.16.0.0

!

ip classless

!

map-class frame-relay FR1

no frame-relay adaptive-shaping

frame-relay cir 768000

frame-relay bc 1000

!

!

!

line con 0

line aux 0

line vty 0 4

password Cisco

login

!

!

voice-port 1/1

!

voice-port 1/2

!

voice-port 1/3

!

voice-port 1/4

!

dial-peer voice 20 vofr

destination-pattern 4

session target serial0 102

!

dial-peer voice 30 pots

destination-pattern 2

port 1/1

!

dial-peer voice 30 pots

destination-pattern 2

port 1/2

!

dial-peer voice 30 pots

destination-pattern 2

port 1/3

!

dial-peer voice 30 pots

destination-pattern 2

port 1/4

!

!

end

Configuration of Router B

!

Version 11.3

No service pad

No service password-encryption

!

hostname Router_B

!

!

network-clock base-rate 64k

no ip domain-lookup

!

!

controller T1 0

framing esf

linecode b8zs

channel-group 0 timeslots 1-24 speed 64

!

controller T1 1

framing esf

clock source internal

linecode b8zs

mode cas

voice-group 1 timeslots 1-4 type e&m-wink-start

!

interface Ethernet0

ip address 172.16.18.1 255.255.255.0

!

interface Serial0

no ip address

shutdown

!

interface Serial1

no ip address

shutdown

!

interface Serial2

no ip address

encapsulation frame-relay

frame-relay traffic-shaping

hold-queue 1024 out

!

interface Serial2.1 point-to-point

ip address 172.16.16.2 255.255.255.252

frame-relay interface-dlci 201 voice-encap 80 class-FR1

!

router eigrp 100

network 172.16.0.0

!

ip classless

!

map-class frame-relay FR1

no frame-relay adaptive-shaping

frame-relay cir 768000

frame-relay bc 1000

!

!

!

line con 0

line aux 0

line vty 0 4

password Cisco

login

!

!

voice-port 1/1

!

voice-port 1/2

!

voice-port 1/3

!

voice-port 1/4

!

dial-peer voice 20 vofr

destination-pattern 2

session target serial0 201

!

dial-peer voice 30 pots

destination-pattern 4

port 1/1

!

dial-peer voice 30 pots

destination-pattern 4

port 1/2

!

dial-peer voice 30 pots

destination-pattern 4

port 1/3

!

dial-peer voice 30 pots

destination-pattern 4

port 1/4

!

!

end

Explanation of Router Commands

In this lab both of the routers are configured similarly Each has one T1 CAS connection to the local PBX and a

Frame-Relay connection to the remote router Since this is true, only Router A will be examined

First, the channel rates must be set 64 Kbps is used in this example

network-clock base-rate 64k

The T-1 controller connecting to the PBX was set for CAS (Channel Associated Signaling) Notice that the

configuration line "voice-group" was used instead of channel-group Only four channels are used in this configuration because only four lines will ever be needed

controller T1 1

framing esf

clock source internal

linecode b8zs

mode cas

voice-group 1 timeslots 1-4 type e&m-wink-start

Frame-Relay Traffic shaping commands must be configured on the serial port

interface Serial2.1 point-to-point

ip address 172.16.16.1 255.255.255.252

frame-relay interface-dlci 102 voice-encap 80 class-FR1

map-class frame-relay FR1

no frame-relay adaptive-shaping

frame-relay cir 768000

frame-relay bc 1000

Voice ports are created based on the number of timeslots configured on the T-1 controller

voice-port 1/1

The dial plan must be configured to direct calls to the correct destination VoFR dial-peers direct traffic to a remote frame-relay router Pots dial-peers direct calls to a specific port on the local router

dial-peer voice 20 vofr

destination-pattern 4

session target serial0 102

!

dial-peer voice 30 pots

destination-pattern 2

port 1/1

[IE-Mult-LS-F02]

[2000-01-31-01]

Copyright © 2000 Genium Publishing Corporation