Suppose this simply scenario: 3 SIP phones A,B,C.
On B is set a redirection (moved temporarily) direct to C.
On C is set a redirection (moved temporarily) direct to B.

If A calls B and B replies with moved temporarily to C.

A INVITE B
A ---------à B

B “Moved temporarily to C”
A ß--------- B

A calls C and B replies with moved temporarily to B.

A INVITE C
A ---------à C

C “Moved temporarily to B”
A ß--------- C

A calls B
A INVITE B
A ---------à B

so it generates an endless loop.

How can I detect and avoid this endless loops?

Does the INVITE contain an header field, analogous to the “Max Forwards”, that I can see to identify a loop and consequently refuse the INVITE?

Thanks for your help,

Daniele