- Description of SIP
- SIP Call Flow
- SIP Pros and Cons
- When to Use SIP
- Dial Plan Considerations
- Implementing SIP Gateways
- Securing SIP Gateways
- Allowing H.323 to SIP Connections
- Troubleshooting Tools
- Case Study: Configuring SIP Between a Gateway and CallManager 5.x
- Review Questions
Case Study: Configuring SIP Between a Gateway and CallManager 5.x
In this case study, SIP is being introduced into the New York and Shanghai networks. The locations will use both SIP and SCCP phones, and a SIP trunk will be configured between the New York CallManager cluster and the Shanghai gateway, shown in Figure 4-12. CallManager 5.x is used to register the SIP phones. The preferred DTMF relay method will be SIP-NOTIFY, but RTP-NTE will be accepted as a second choice.
Figure 4-12 SIP Case Study Network Diagram
For redundancy, the Shanghai gateway has dial peers to two of the CallManager servers. One CallManager IP address is configured under the UA, to demonstrate that command. The gateway will register its network analog phones with registrar servers at 10.10.10.19 and 10.10.10.20. HTTP digest authentication is configured.
All SIP traffic will use interface Fa0/0 as its source IP address. Large packets will switch from UDP to TCP as their transport protocol to avoid UDP fragmentation.
Example 4-14 shows the configuration of SIP and the SIP trunk on the Shanghai gateway. POTS dial peers to connect to the PBX are not shown in this example. CallManager configuration is outside the scope of this case study.
Example 4-14. SIP Case Study
Shanghai-GW(config)#sip-ua Shanghai-GW(config-sip-ua)#sip-server ipv4:10.10.10.11 Shanghai-GW(config-sip-ua)#registrar ipv4:10.10.10.19 Shanghai-GW(config-sip-ua)#registrar ipv4:10.10.10.20 secondary Shanghai-GW(config-sip-ua)#authentication username NYCServ1 password C1sc0 realm NYC-SIP ! Shanghai-GW(config)#voice service voip Shanghai-GW(conf-voi-serv)#sip Shanghai-GW(conf-serv-sip)#bind all source-interface fa0/0 Shanghai-GW(conf-serv-sip)#transport switch udp tcp ! Shanghai-GW(config)#dial-peer voice 2121 voip Shanghai-GW(config-dial-peer)#destination-pattern 21255521.. Shanghai-GW(config-dial-peer)#session target sip-server Shanghai-GW(config-dial-peer)#session protocol sipv2 Shanghai-GW(config-dial-peer)#dtmf-relay sip-notify rtp-nte Shanghai-GW(config-dial-peer)#preference 1 ! Shanghai-GW(config)#dial-peer voice 2122 voip Shanghai-GW(config-dial-peer)#destination-pattern 21255521.. Shanghai-GW(config-dial-peer)#session target 10.10.10.12 Shanghai-GW(config-dial-peer)#session protocol sipv2 Shanghai-GW(config-dial-peer)#dtmf-relay sip-notify rtp-nte Shanghai-GW(config-dial-peer)#preference 2