Seminar 44

V0IP (Voice over Internet Protocol)Firstly PSTN (Public Switch Telephone Network) was developed for the voice transmission of data. And the PSTN is very expensive solution for the voice transmission of long distance.For example

PTCL in PakistanSo Internet is a solution for the transmission of user data. FTP, HTTP, or SMTP etcNow we are using internet for the transmission of Voice by converting analog voice signal into digital signal and send on the internet.We send voice by putting it on the internet protocol and send it to the internet it is called Voice Over IP.

Domain Name www.corvit.com DNS server converts 64.10.23.25Telephone No. 111 sever converts 10.1.1.1

VOIP Hardware

FXS (Foreign Exchange Station)

FXS is a card which is used for the voice transmission over internet It is a module and plug on the module router (above 3600 series).It is an analog voice interface.It has two RJ-45 ports for the telephone cables.FXS is tone generating device.

Coding and Decoding

The conversion of Analog signals into Digital Signals and Digital to Analog is done by the Codec.

1 G.711 Codec Used by PSTN

2 G.729 Codec Used by VoIP

VoIP is using better Codec than the PSTN how let us see.

Internet Cloud

LahoreOffice

New York Office

Telephone Telephone No 111 No 222

S0/0

S0/0E0 E0

10.1.1.1

10.1.1.2

Analog Signals

FXS FXS

Analog SignalsDigital Signals

1/1/1 1/1/1

G.711

Describes the 64-kbps PCM voice coding technique. In G.711, encoded voice is already in the correct format for digital voice delivery in the PSTN or through PBXs. Described in the ITU-T standard in its G-series recommendations

G.729

Describes CELP compression where voice is coded into 8-kbps streams. There are two variations of this standard (G.729 and G.729 Annex A) that differ mainly in computational complexity; both provide speech quality similar to 32-kbps ADPCM. Described in the ITU-T standard in its G-series recommendations.

PCM (Pulse Code Modulation)

The process of PCM (Pulse Code Modulation) will be happened between the routers PSTN is using the codec in all over the world is G.711

Configuration on the Router

In the above topology there are two remote sides and we have to configure a setup of Voice over IP between both sides.

First of all we will perform two types of configurations on both the Routers.

At Lahore Router we have to Tell it about 111 and 222

For 111 Call send it out from port 1/1/1 it is called POTS for Router AFor 222 Call send it on the IP address 10.1.1.2 it is called VoIP Similarly

At New York Router we have to Tell it about 222 and 111

For 222 Call send it out from the port 1/1/1 it is called POTS for Router BFor 111 Call send it on the IP address 10.1.1.1 It is called VoIP

What is POTS?

Internet Cloud

LahoreOffice

New York Office

Telephone No 222

S0/0

S0/0E0 E0

10.1.1.1

10.1.1.2

Analog Signals

FXS FXS

Analog SignalsDigital Signals

1/1/1 1/1/1

Telephone No 111

POTS stand for Plain Old Telephone ServicesDial peer connected via a traditional telephony network. POTS peers point to a particular voice port on a voice network device.

What is VOIP?

VOIP stands for Voice over Internet ProtocolThe capability to carry normal telephony-style voice over an IP-based internet with POTS-like functionality, reliability, and voice quality. VoIP enables a router to carry voice traffic (for example, telephone calls and faxes) over an IP network. In VoIP, the DSP segments the voice signal into frames, which then are coupled in groups of two and stored in voice packets. These voice packets are transported using IP in compliance with ITU-T specification H.323.

For Lahore Router A

1 Dial Peer for VOIP 222 (Telephone Number of New York Router) isDestination Pattern

2 Dial Peer for POTS 111 (Telephone Number of Lahore Router) isDestination Pattern

3 IPV4 10.1.1.2 (IP address of serial interface of New York Router) isSession Target

4 Port for 111 is 1/1/1 which is Port of FXS ModuleRouter A

Step 1 (Dial Peer for VOIP)

LahoreOffice

E0

FXS1/1/1

Telephone No 111 Call from 111 toRouter A is called POTS

LahoreOffice

New York Office

S0/0

S0/0E0 E0

10.1.1.1

10.1.1.2

Analog Signals

FXS FXS

Analog SignalsDigital Signals

1/1/1 1/1/1

Call from 111 to 222 is called VOIP

Telephone No 111

Telephone No 222

Internet Cloud

routerA>routerA>enablerouterA#routerA#configure terminalrouterA(config)#routerA(config)#dial-peer-voice 1 voiprouterA(config-dial-peer)#routerA(config-dial-peer)#destination pattern 222routerA(config-dial-peer)#routerA(config-dial-peer)#session target ipv4: 10.1.1.2routerA(config-dial-peer)#routerA(config-dial-peer)#exitrouterA(config)#

Step 2 (Dial Peer for POTS)

routerA(config)#routerA(config)#dial-peer-voice 2 potsrouterA(config-dial-peer)#routerA(config-dial-peer)#destination-pattern 111routerA(config-dial-peer)#routerA(config-dial-peer)#port 1/1/1routerA(config-dial-peer)#routerA(config-dial-peer)#endrouterA#

Router B

Step 1 (Dial Peer for VOIP)

If we have to assign any telephone number (111, 222 or 123 etc.) to any router then in Global Config Mode we have to configure a Dial Peer for each Number.1 is any number for 222If there is another number 333 or 111 etc then we configure for each number a different number 2, 3 etc.

Destination PatternAs we have to dial 222 (Router B in New York) from Lahore (Router A) there for we will configure destination pattern number 222 at Lahore (Router A)

VoIP Dial Peer Mode

Global Config Mode

Privileged Mode

Global Config Mode

POTS Dial Peer Mode

Session Target10.1.1.2 is Session Target for 111 and as we are using IP Version 4 so we should have to mansion it the Version of IP.

Port Number of FXS Card1/1/1 is the Port No of FXS to which the Telephone Connector is connected.

routerB>routerB>enablerouterB#routerB#configure terminalrouterB(config)#routerB(config)#dial-peer-voice 2 voiprouterB(config-dial-peer)#routerB(config-dial-peer)#destination pattern 111routerB(config-dial-peer)#routerB(config-dial-peer)#session target ipv4: 10.1.1.1routerB(config-dial-peer)#routerB(config-dial-peer)#exitrouterB(config)#

Step 2 (Dial Peer for POTS)

routerB(config)#routerB(config)#dial-peer-voice 1 potsrouterB(config-dial-peer)#routerB(config-dial-peer)#destination-pattern 222routerB(config-dial-peer)#routerB(config-dial-peer)#port 1/1/1routerB(config-dial-peer)#routerB(config-dial-peer)#endrouterB#

Router A

If we have to assign any telephone number (111, 222 or 123 etc.) to any router then in Global Config Mode we have to configure a Dial Peer for each Number.2 is any number for 111If there is another number 333 or 222 etc then we configure for each number a different number 2, 3 etc.

Destination PatternAs we have to dial 111 (Router A in Lahore) from New York (Router B) there for we will configure destination pattern number 111 at New York (Router B)

VoIP Dial Peer Mode

Global Config Mode

Privileged Mode

Global Config Mode

POTS Dial Peer Mode

Session Target10.1.1.1 is Session Target for 222 and, as we are using IP Version 4 so we should have to mansion it the Version of IP.

Port Number of FXS Card1/1/1 is the Port No of FXS to which the Telephone Connector is connected.

routerA>routerA>enablerouterA#routerA#configure terminalrouterA(config)#routerA(config)#dial-peer-voice 1 voiprouterA(config-dial-peer)#routerA(config-dial-peer)#destination pattern 222routerA(config-dial-peer)#routerA(config-dial-peer)#session target ipv4: 10.1.1.2routerA(config-dial-peer)#routerA(config-dial-peer)#endrouterA(config)#routerA(config)#dial-peer-voice 2 potsrouterA(config-dial-peer)#routerA(config-dial-peer)#destination pattern 111routerA(config-dial-peer)#routerA(config-dial-peer)#port 1/1/1routerA(config-dial-peer)#routerA(config-dial-peer)#endrouterA#routerA#exitrouterA>

Router B

routerB>routerB>enablerouterB#routerB#configure terminalrouterB(config)#routerB(config)#dial-peer-voice 2 voiprouterB(config-dial-peer)#routerB(config-dial-peer)#destination pattern 111routerB(config-dial-peer)#routerB(config-dial-peer)#session target ipv4: 10.1.1.1routerB(config-dial-peer)#routerB(config-dial-peer)#exitrouterB(config)#routerB(config)#dial-peer-voice 1 potsrouterB(config-dial-peer)#routerB(config-dial-peer)#destination pattern 222routerB(config-dial-peer)#routerB(config-dial-peer)#port 1/1/1routerB(config-dial-peer)#routerB(config-dial-peer)#endrouterB#routerB#exitrouter>

RouterA>RouterA>enableRouterA#RouterA#configure terminalRouterA(config)#RouterA(config)#dial-peer-voice 1 voipRouterA(config-dial-peer)#RouterA(config-dial-peer)#destination pattern 222RouterA(config-dial-peer)#RouterA(config-dial-peer)#session target ipv4: 10.1.1.2RouterA(config-dial-peer)#RouterA(config-dial-peer)#endRouterA(config)#RouterA(config)#dial-peer-voice 2 potsRouterA(config-dial-peer)#RouterA(config-dial-peer)#destination pattern 111RouterA(config-dial-peer)#RouterA(config-dial-peer)#port 1/1/1RouterA(config-dial-peer)#RouterA(config-dial-peer)#endRouterA#RouterA