When a request is being sent, the
RECORD-ROUTE header records the address of each of the entities in the call path.
The response then inserts these addresses in the ROUTE headers (there are typically
multiple headers).
The headers are listed in the order of the route. In other words, the addresses are
shown in the same order they are routed through. The routers then use this for routing
the responses to the next hop in the network.
ROUTE:
Session Initiation Protocol (SIP) 81
Server This header allows the server (the recipient of a request) to communicate the
software version being used by the server to process the request. There are many uses
for this information, depending on implementation.
Care should be taken with this header, as information regarding software versions
could be a security risk. Hackers could use this information to obtain the version of the
Symbian operating system resident on a cell phone, for example, and then send a virus
or Trojan to that device. Operators should use encryption to prevent this information
from being read by any other than the end devices in a session.
SERVER: Symbian OS 8.0
Subject This is much like the subject line in e-mail. It is provided as a means of sharing
additional information about the session for display to the user. For example, if
used for an emergency broadcast feature, the SUBJECT header would contain the
actual alert message (such as ???Thunderstorm warnings for Johnston County???) while
the PRIORITY header would contain the priority for the session.
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