1. Two SIP Trunks at two different locations were set up for a continuous run.
2. TTBS provided the SIP Trunk over Ethernet with SDH ring architecture.
3. The SIP Trunk was terminated over a Session Border Controller (SBC) at the last mile.
4. To ensure redundancy, TTBS provided SIP Trunk 1 with 60 channels at one location and SIP Trunk 2 separately terminating at the SBC.
5. The Trunk bandwidth was created to support the aggregated SIP to achieve 100% concurrency.
6. TTBS SIP Trunk was a P2P circuit with /30 IP address assigned by TATA. The same IP address was to be transferred to the customer PBX’s NIC interface.
7. Codec on both trunks was configured to comply with the G.711 A law.
8. The Dual-Tone-Multi-Frequency (DTMF) was set at RFC 2833.
9. The “P-Preferred-Identity” header was included in all SIP INVITEs for correct DID CLIP display on the outgoing calls.
10. DID number sending (DNIS) on SIP INVITE “To” header on incoming calls.
11. A keep-alive mechanism through SIP options was implemented. The expected response was SIP 60 Ok from the CPE device.
12. TTBS system also provided parameters such as Customer IP (configured at the NIC port of the SBC), Gateway IP, SIP Server, IP Subnet Mask, Username, Password and DID Range.