Chapter 10. SIP Services
"0" or an empty field means that SIP over TCP or TLS cannot be used to the Telecommuting Module.
Allowed number of concurrent sessions
Enter the number of concurrent SIP sessions which the Telecommuting Module should han- dle.
Leave the field empty to allow as many sessions as there are SIP traversal licenses on the Telecommuting Module (number displayed inside parantheses). You can purchase additional SIP traversal licenses from your retailer.
Media Configuration
3Com VCX IP Telecommuting Module supports UDP and TCP media streams.
Set limitations for the media streams through the Telecommuting Module.
Limitation of sender of media streams
This setting allows you to define who can send media in a SIP call. This is never negotiated in the SIP signaling, and can theoretically be a completely different unit from the one receiving the media.
The Telecommuting Module usually locks a media stream to the first sender IP address and port (for security reasons). Some SIP clients change ports during the first media stream pack- ets, which will block the media stream from being let through the Telecommuting Module. There are also scenarios where the media stream sender is changed to an entirely new sender.
You can select for the Telecommuting Module to Lock IP address and port to first sender, which will render the behaviour described above. Only allow receiving IP address, but multiple ports will allow media only from the IP address which will receive the media stream in the opposite direction, but allow for port changes on that IP address. Allow multiple sender IP addresses and ports lets the media stream through even if ports and/or IP addresses change.
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