





Important Facts About VoIP
Here are some important facts about the Passport VoIP feature.
- Passport VoIP does not interoperate with MICOM V/IP, nor does it interoperate with other implementations of Voice over IP.
- VoIP operation is not supported over RFC 1490 PVCs.
- The Passport 6400 Voice Networking Call Server (VNCS) does not support VoIP. However, it will transparently pass the VoIP packets to their correct destination.
- All voice packets generated by VoIP have RFC 1889-compliant Real-time Transport Protocol (RTP) headers. The Type Of Service (TOS) field in the IP header (RFC 1349 and RFC 1060) is chosen to request a path through the network that is optimized for low delay.
- Transparent CCS HTDS is not supported in this release.
- Passport VoIP is supported only on NAC/NAS networks. RSI/RSA networks do not support VoIP.
- If Speech Activity Detection (SAD) is disabled and call bundle size (a VoIP parameter) is set to 1, a maximum of 15 VoIP calls can be switched through the central site. When SAD is enabled and the call bundle size is set to 4 (the default value), up to 60 VoIP calls can be switched through the central site.
- RFC 1490 links do not support IP prioritization. Voice quality over an RFC-1490 link cannot be assured as it can over a PANL link.