8.1.1.6 Max-Forwards
The Max-Forwards header field serves to limit the number of hops a
request can transit on the way to its destination. It consists of an
integer that is decremented by one at each hop. If the Max-Forwards
value reaches 0 before the request reaches its destination, it will
be rejected with a 483(Too Many Hops) error response.
A UAC MUST insert a Max-Forwards header field into each request it
originates with a value that SHOULD be 70. This number was chosen to
be sufficiently large to guarantee that a request would not be
dropped in any SIP network when there were no loops, but not so large
as to consume proxy resources when a loop does occur. Lower values
should be used with caution and only in networks where topologies are
known by the UA.
3. Max-Forwards check
The Max-Forwards header field (Section 20.22) is used to limit the
number of elements a SIP request can traverse.
If the request does not contain a Max-Forwards header field, this
check is passed.
If the request contains a Max-Forwards header field with a field
value greater than zero, the check is passed.
If the request contains a Max-Forwards header field with a field
value of zero (0), the element MUST NOT forward the request. If
the request was for OPTIONS, the element MAY act as the final
recipient and respond per Section 11. Otherwise, the element MUST
return a 483 (Too many hops) response.
21.4.21 483 Too Many Hops
The server received a request that contains a Max-Forwards (Section
20.22) header field with the value zero.
Hat die Suche hier im Forum nach 483 irgendwas gebracht?
