The SIP transaction model includes a number of request and response messages, each of which contains a method field that denotes the purpose of the message.
Before You Begin |
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For background information, read Understanding the SIP ALG. |
JUNOS Software supports the following method types and response codes:
For example, if user A in a private network refers user B, in a public network, to user C, who is also in the private network, the SIP ALG allocates a new IP address and port number for user C so that user C can be contacted by user B. If user C is registered with a registrar, however, its port mapping is stored in the ALG NAT table and is reused to perform the translation.