Wireless Ad Hoc VoIPThesis by: Patrick Stuedi & Gustavo Alonso

Presentation by: Anil Kumar Marukala &Syed Khaja Najmuddin Ahmed

Introduction• Implementing VoIP over mobile ad-hoc network.• Why ?

• Calls inside MANET are always possible.• If one node in MANET is connected to internet, VoIP over

internet can be used by all nodes.

Contd..

• Converting any devices (laptops, iPAQ handhelds, mobile phones) to wireless phone by installing a small software (kphone).

• SIPHoc which uses middleware to make VoIP calls is used instead of SIP.

System Overview• Its build on SIPHoc• It is based on five components running as independent

operating system processes within a node in the MANET. • VoIP application: Any SIP compatible VoIP client• SIPHoc Proxy: SIP interface but implements MANET

functionality.•Serves as Local Outbound Proxy.

Contd…• MANET SLP Layer: Provides SLP (Service Location Protocol) interface but

implements decentralized service lookup functionality.• Piggybacks service information onto routing messages

• Gateway Provider: Publishes SLP gateway service to provide information of a node with internet connectivity

• Opens two tunnel server ready to accept connection• Connection Provider: manages connections of the node to the internet

• Periodically searches for gateway service and opens two tunnel connection to the node offering tunnel server.

Making calls within the MANET

• Registering with SIP proxy. outbound of VoIP is configured so its registered with local SIPHoc proxy.• SIPHoc proxy will Advertise itself with MANET SLP.• Other users will also register with SIPHoc Proxy.• This information is available to all nodes in network since

MANET SLP is distributed SLP designed for ad hoc networks.• In MANET SLP information is exchanged via routing message

piggybacking so, right plugin for the routing protocol is to be loaded.• SIP call setup requests are routed through SIPHoc Proxy,

target’s address is determined by consulting MANET SLP, it retrieves end point address using piggyback routing and forwards request to target SIPHoc Proxy of the target node. Then request is forwarded and VoIP application rings.

Phone calls to/from Internet• SIPHoc allows setting up SIP connection to and from the

internet the Internet by using MANET nodes connected to the Internet as gateways.• Official SIP phone number can used within MANET and for the

internet VoIP.• Compatible with SIP Providers like siphoc.ch,netvoip.ch but

when SIP Provider require special outbound Proxy it cannot work e.g, polyphone.ethz.ch.

Deployment

• Laptops (Debian, i386) and iPAQ handhelds (Familiar Linux, ARM/XSCALE)• First prototype was iPAQ/h5000 under Familiar Linux.• C version of SIPHoc Proxy was used and came up with a

system which included 4 services and a footprint of 1.2M and 20 shared libraries used by the services.

Conclusion

• The paper showed how communication between devices in Ad Hoc networks using VoIP services has been established.• This application can be used at the places where proper

infrastructure is not available.• This application if implemented after improvements and

further research calls can be made almost free of cost.