The SIP ALG for LCOS has the following features:
- No local registration
The SIP proxy does not provide registration for SIP endpoints. Instead, it mediates the registrations directly to the approved SIP domains.
Important: This means that it is impossible to set up a line backup over alternative voice lines (analog, ISDN).
- Transparency for SIP extensions
The SIP ALG also transmits unknown, non-standard header elements to enable the SIP messages to be communicated between terminal devices and SIP PBXs.
Important: The SIP ALG determines an unambiguous destination for every SIP message. Forking (communication between multiple devices of the same identity) is handled upstream. The SIP ALG merely provides transparent forwarding of these data packets.
