Codec Freedom -- Specifications -- Redirecting the Voice Connection with SIP
Just like it is possible to change the codec of the communication at hand, so it
is possible to modify the signaling properties. To this end, the treatment of
message/sip should be interpreted as aimed at the local phone,
provided that its Content-Disposition is set to
addresses used in field like
To: may be
tel: URIs and may or may not
need renaming before forwaring to local infrastructure. The remote party may
also drop the headers describing the partners, in which case each local end
would substitute an address that is understood by the local endpoint to indicate
transition over the modified G.711 connection.
Remote SIP inquiries should never be taken lightly, and be scrutinised for security impact. It is probably safe to consider an incoming SIP message over AMQP as compatible with the SIP message that would pass over the Internet, and through our local proxies. Any SDP attachments can be treated in the same manner as when they would have been passed over AMQP.