The dialog cannot be established until a 200 OK has been received
as a response and the ACK has been sent as the final sequence in the handshake
process. This response would be sent prior to the 200 OK.
?– 405 Method Not Allowed This is sent when the recipient of a request recognizes
a method used in the request but does not support it.
?– 416 Unsupported URI Scheme The recipient of a request does not understand
the URI format being used in the request.
?– 420 Bad Extension The recipient of a request does not understand the OPTIONTAGS
in the PROXY-REQUIRE header.
?– 481 Call/Transaction Does Not Exist This is sent by the recipient of a BYE
method that cannot be correlated to a call or session in progress.
?– 483 Too Many Hops This is sent by stateful proxies when they receive a request
and the MAX-FORWARDS header contains a value of 0.
?– 486 Busy Here This is sent by the recipient of a request when they do not wish
to accept the requested session. This might be seen, for example, when a request is
sent to multiple devices and one of the devices is rejecting the request.
?– 487 Request Terminated This is sent by the recipient of a request when the
internal timer expires prior to a 200 OK response being sent.
?– 488 Not Acceptable Here This is used to reject an offer contained within a
request. The reason for rejecting the offer will be contained in the response.
Pages:
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160