Implementing a Voice Over Internet (Voip) Telephony System

Final Project report

Presented by: Md. Manzoor Murshed

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Objectives

Voice Over IP SIP H.323 MGCP Simulation using Westplan Conclusion

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Voice over IP

provide the functionality required to set up, manage, and tear down calls and connections;

be scalable to support a very large number of registered endpoints (in the order of billions worldwide), and a very large number of simultaneous calls (in the order of millions worldwide);

support network management features for policy control, accounting, billing, etc;

provide a mechanism to communicate and set up the Quality of Service requested by the end points;

be extensible to help with adding new features easily; support interoperability among different vendors’

implementations, among different versions of the signaling protocol, and with different signaling protocols.

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Multimedia Protocol Stack

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Registration Process

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SIP COMPONENTS AND MESSAGES

Invite: Indicates that the user or service is being invited to participate in a session.

Ack: Confirms the client has received a final response to an Invite request.

Options: Is used to query a server about its capabilities.

Bye: Is sent by a User Agent Client to indicate to the server that it wished to release the call.

Cancel: Is used to cancel a pending request. Register: Is used by a client to register an address

with a SIP server

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SIP COMPONENTS AND MESSAGES 1xx: Informational- The request has been received

and processing is continuing. 2xx: Success – An Ack, which indicated that the

action was successfully received, understood, and accepted.

3xx: Redirection – Further action is required to process this request.

4xx: Client Error – The request contains bad syntax and cannot be fulfill at this server.

5xx: Server Error – The server failed (for internal reasons) to fulfill an apparently valid request.

6xx: Global Failure – The request cannot be fulfilled at any server.

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Architecture

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Signaling Systems and Messages

IP TelephoneVoip-PSTNGateway

PSTNPSTNAnalog Telephone

Voip-Neowork Signaling Inter-exchange Signaling(SS&)

Subscriber LoopSIgnaling

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THE H.323 MULTIMEDIA STANDARD

H.323 Terminal

H.323 Gatekeeper

H.323 Gateway H.323 Terminal H.323 Terminal

H.323 MCU

Packet Based Network

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SIMULATION #1 WITH WESTPLAN SIMULATOR

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Link Summary

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Optimization results

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Link Traffic analysis:

Node Transmission medium Entry Network resource Entry network voice channels

Ames PSTN - Waterloo IPBX T1 (24 B channels); 1 trunk 24

DesMoines IPBX - Waterloo IPBX Voice over IP (PPP) 512 kbps 40

Ames PSTN - DesMoines IPBX T1 (24 B channels) 1 trunk 24

DesMoines IPBX - Fayette Gateway Voice over IP (PPP) 256 kbps 20

Fayette Gateway - West Union PBX Analogue 15 trunks 15

Independence PSTN - West Union PBX T1 (24 B channels) 1 trunk 24

Fayette Gateway - Independence PSTN T1 (24 B channels) 1 trunk 24

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Link and Traffic Analysis

Node Link type Entry network facilities

Entry network channels

Busy hour traffic

Blocking experienced

Optimum voice channels

Entry network facilities

Ames PSTN - Waterloo IPBX

T1 (24B) 1 trunk 24 25.100 0.170 36 2 trunks

DesMoines IPBX - Waterloo IPBX

VoIP (PPP) 512 kbps 40 15.200 0.000 24 302 kbps

Ames PSTN - DesMoines IPBX

T1 (24B) 1 trunk 24 229.360 0.896 252 11 trunks

DesMoines IPBX - Fayette Gateway

VoIP (PPP) 256 kbps 20 43.760 0.560 57 716 kbps

Fayette Gateway - West Union PBX

Analogue 15 trunks 15 32.760 0.564 45 45 trunks

Independence PSTN - West Union PBX

T1 (24B) 1 trunk 24 78.800 0.701 95 4 trunks

Fayette Gateway - Independence PSTN

T1 (24B) 1 trunk 24 11.000 0.000 19 1 trunk

Node Busy hour offered traffic

Entry network blocking

Required voice channels

Required link resource

Ames PSTN - Waterloo IPBX 25.100 Erlangs 0.170 36 2 T1 trunks DesMoines IPBX - Waterloo IPBX 15.200 Erlangs 0.000 24 302 kbps Ames PSTN - DesMoines IPBX 229.360 Erlangs 0.896 252 11 T1 trunks DesMoines IPBX - Fayette Gateway 43.760 Erlangs 0.560 57 716 kbps Fayette Gateway - West Union PBX 32.760 Erlangs 0.564 45 45 analogue

trunks. Independence PSTN - West Union PBX 78.800 Erlangs 0.701 95 4 T1 trunks Fayette Gateway - Independence PSTN 11.000 Erlangs 0.000 19 1 T1 trunk

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Conclusion

Questions?