Juniper NETWORK AND SECURITY MANAGER 2010.4 - CONFIGURING SCREENOS DEVICES GUIDE REV 01 Manual page 307

Copyright © 2010, Juniper Networks, Inc.
Table 70: SIP Request Methods (continued)
Method
Types/Response
Codes Description
BYE A user sends a BYE request to
abandon a session. A BYE request
from either user automatically
terminates the session.
CANCEL A user sends a CANCEL request to
cancel a pending INVITE request. A
CANCEL request has no effect if the
SIP server processing the INVITE had
sent a final response for the INVITE
before it received the CANCEL.
REGISTER A user sends a REGISTER request to
a SIP registrar server to inform it of
the current location of the user. A SIP
registrar server records all the
information it receives in REGISTER
requests and makes this information
available to any SIP server
attempting to locate a user.
Info Used to communicate mid-session
signaling information along the
signaling path for the call.
Subscribe Used to request current state and
state updates from a remote node.
In NAT mode, the address in the
Request-URI is changed to a private
IP address if the message is coming
from the external network into the
internal network.
Chapter 9: Voice Over Internet Protocol
Modified Fields
In NAT mode, the IP addresses in
the Via, From, To, Call-ID, Contact,
Route, and Record-Route header
fields are modified.
In NAT mode, the IP addresses in
the Via, From, To, Call-ID, Contact,
Route, and Record-Route header
fields are modified.
In NAT mode, REGISTER requests
are handled as follows:
REGISTER requests from an
external client to an internal
registrar—When the SIP ALG
receives the incoming REGISTER
request it translates the IP
address, if any, in the
Request-URI. Incoming
REGISTER messages are allowed
only to a MIP or VIP address. No
translation is needed for the
outgoing response.
REGISTER requests from an
internal client to an external
registrar—When the SIP ALG
receives the outgoing REGISTER
request it translates the IP
addresses in the To, From, Via,
Call-ID, and Contact: header
fields. A backward translation is
performed for the incoming
response.
In NAT mode, the IP addresses in
the Via, From, To, Call-ID, Contact,
Route, and Record-Route header
fields are modified.
The IP addresses in Via, From, To,
Call-ID, Contact, Route, and
Record-Route header fields are
modified.
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