1. Integrating Voice with Data Over a Leased Line
Quick Start Guide
Wael
Valencia Community College

2. Major Configuration Tasks
Step 1 Configure your IP network to support real-time voice traffic. Before you move to the next step, ping the remote router to make sure you have an IP connection.
Step 2 Configure your router to support voice ports: Foreign exchange station (FXS). The default voice-port values are usually adequate for FXS
Step 3 Enter configuration mode to configure your router for VoIP traffic.
Step 4 Save the configuration.
Step 5 Establish a dial plan to determine how the call can be routed. Use the dial-peer voice command to define dial peers and to implement the dial plan.
Step 6 Fine-tune your network to adequately support VoIP by configuring a series of protocols and features for quality of service (QoS).

3. Voice and data on IP Networks
How to configure Cisco modular routers to carry voice traffic such as telephone calls and faxes over an IP network

4. Installing Voice Network Modules
Two-Slot Voice Network Module
Convert telephone voice signals into a from that can be transmitted over an IP network

5. Installing Voice Network Modules

6. Voice Interface Cards There are three types of VICs:
An FXS (Foreign Exchange Station): Connects to standard Phone or Fax Machine.
An FXO (Foreign Exchange Office): Connects local calls to a PSTN Central Office.
E&M (Ear and Mouth): Connects remote Calls from an IP network to a PBX for local Distribution

7. Connecting Voice Interface Cards to the Network
RJ11
RJ11
RJ48S

8. Connecting a Voice Gateway to a PBX Using E&M
An Ear and Mouth (E&M) interface is used to support tie-line facilities or signals between telephone switches. The E&M voice interface card (VIC) is mostly used to integrate VoIP with the legacy voice solution, connecting the Cisco router to a PBX.

9. Voice Port Numbering Example:
Suppose you install a two-slot voice network module in the upper right slot of a Cisco 3640 router, and install two VICs in the module. Each VIC has two ports. From right to left, these ports would be numbered 2/0/0, 2/0/1, 2/1/0, and 2/1/1.

10. Configuring FXS Interfaces (West)
Local Dial Peers:
Associating a telephone number to a voice port
For instance, if a call comes in for , the router needs to know that this phone is connected to FXS VIC 2/0/0.
Cisco IOS uses objects called dial peers to accomplish this task
Configuring dial peers is similar to configuring static IP routes
Dial peers are identified by numbers: 32-bit field
Dial peer numbers are also known as dial peer tags

11. Configuring FXS Interfaces (West)
This type of dial peer is called POTS
A POTS dial-peer associates a physical voice port with a local telephone device
VoIP dial-peers will be discussed later
However, the dial-peer command always takes the argument voice
Destination Pattern (dest-pat) = telephone number, and always begin with + sign
A destination pattern can also include other signs such as #, or *. (coming up)

12. Configuring FXS Interfaces (East)

13. Configuring FXS Interfaces (East)

14. Checking the Configuration
You should now be able to place calls between telepnones connected to the same router.
Use the command: router# show dial-peer voice
The above command verifies that the data you configured is correct

15. Wild cards and Number Expansion
Office PBXs are configured so a user can dial a local call within the same PBX by dialing the extension only
For example dial five-digit extension instead of
The same shortcut can be provided on a VoIP network by using the number-expansion command.

16. Wild cards and Number Expansion
For instance, to expand into , enter the following command:
West(config)# num-exp
Wild cards can also be used in number expansion as follows:
West(config)# num-exp 5… ….
The period (.) is used as a wild-card character representing a single digit.
Use the command: west# show num-exp to verify your configuration.
Now, you should be able to dial using the extension number.

17. Calling between Routers
West and East offices would like to send voice traffic over the same IP network they use to send data traffic.
IP routers know how to locate IP addresses on the network, but they do not know how to locate telephone numbers.
To route an outgoing voice call over this connection, the West router has to associate a telephone number in the East office with the IP address of the East router.

18. Remote Dial Peers/VoIP Dial Peers
This goal is accomplished by configuring Voice Over IP Dial Peers
The term VoIP means that the dial peer associates a telephone number with an IP address.
As opposed to POTS dial peers which associates a physical voice port such as FXS with a telephone number

19. Remote Dial Peers/VoIP Dial Peers
Remote Location
Phone #
Destination Pattern
IP add
Dial Peer Tag
East
501
502

20. Remote Dial Peers with Wild Cards
Remote Location
Phone #
Destination Pattern
IP add
Dial Peer Tag
East
xxxx ….
501
One Remote Dial Peer to reach all phones on the East Router

21. Even Better, Configure Number Expansion
Remote Location
Phone #
Destination Pattern
IP add
Dial Peer Tag
East
501
502
With Wild Cards
Remote Location
Phone #
Destination Pattern
IP add
Dial Peer Tag
East
xxxx ….
501
West(config) # num-exp 8… ….

22. Configuration Commands
Reset the router:
if your router displays this message: “would you like to enter the initial configuration dialog? [ys]:” then it has already been reset. Just answer no and move on to step 3.
If your router asks for a password try one of the following: conpass, compass, cisco, or class (if configured, you have to enter a password for the console and another to get to privileged mode)
West>enable
West#erase start
Westr#reload
Configure the serial interface with an IP address
router> enable
Router# config t
Router(config) # hostname West
West(config) # int s0/0 (or S0/1, depending on where your cable is connected)
West(config-if) # i p address
West(config-if) # clock rate (if DCE)
West(config-if) # no shut
Save your config
West# copy run start
Verify that your interface is up:
West# show ip int brief

23. Configuration Commands
Configure VoIP dial peers:
West(config) # dial-peer voice 501 voip
West(config-dial-peer) # dest-pat ….
West(config-dial-peer) # session-target ipv4:

24. Apply the same config to East router
Remote Location
Phone #
Destination Pattern
IP add
Dial Peer Tag
West
Remote Location
Phone #
Destination Pattern
IP add
Dial Peer Tag
East
West(config) # num-exp

25. Apply the same config to East router
Reset the router:
if your router displays this message: “would you like to enter the initial configuration dialog? [ys]:” then it has already been reset. Just answer no and move on to step 3.
If your router asks for a password try one of the following: conpass, compass, cisco, or class (if configured, you have to enter a password for the console and another to get to privileged mode)
West>enable
West#erase start
Westr#reload
Configure the serial interface with an IP address
router> enable
Router# config t
Router(config) # hostname West
West(config) # int s0/0 (or S0/1, depending on where your cable is connected)
West(config-if) # i p address _________________________
West(config-if) # clock rate (if DCE)
West(config-if) # no shut
Save your config
West# copy run start
Verify that your interface is up:
West# show ip int brief
Ping the remote Interface

26. Apply the same config to East router
West(config) # dial-peer voice
West(config-dial-peer) # dest-pat
West(config-dial-peer) # session-target ipv4:

27. Configuring the IP Network for Real-Time Voice Traffic
VoIP Commands require the IP Plus, Desktop Plus, or Enterprise Plus image, Cisco IOS Release 11.3(1)T or later
Voice traffic is much more sensitive to timing variations than data traffic
You might need to configure your data network so voice packets are not lost or delayed

28. Configuring the IP Network for Real-Time Voice Traffic
Three important methods of improving QoS (The level of network performance needed for VoIP connections)
Resource Reservation Protocol (RSVP)
Multilink PPP Interleaving
Real Time Transport Protocol header compression (RTP header compression)

29. PPP or HDLC Serial Links
Do we Need QOS
PPP or HDLC Serial Links
Fast Ethernet

30. When to Use RSVP
Serial links between two routers using HDLC or PPP encapsulation (Such as the case in leased lines)
Links Slower than 2 Mbps and with high utilization

31. Requesting RSVP
After configuring RSVP on the WAN interface as we did back on slide 13,
Configure each VoIP dial peer to request an RSVP session, using the req-qos command:
West(config) # dial-peer voice 501 voip
West (config-dial-peer) # req-qos controlled-load
Apply the same config to the VoIP dial peer at the East router
Check and verify your configuration on both routers using the command: west# show dial-peer voice

32. When to Use Multilink PPP Interleaving?
ISDN links BRI or PRI
Links Slower than 2 Mbps

33. When to Use RTP Compression
Can be combined with RSVP or with Multilink PPP Interleaving
Use when you are trying to save bandwidth on slow serial links (less than 2 Mbps)
Configuration:
Router(config-if)# ip rtp header-compression
Compression must be enabled at both ends of the serial link.

34. Converged Network Lab