Asterisk and SIPP - Server 503 - retrans_pkt

I am currently trying to use sipp 3.1 (windows) to test on a functionnal * box, running

I am using the default client scenario to call an ivr that plainly plays music, until a party hangs up.

When I am running 1 call, 1 simultaneous, everything is fine. When I run 2 calls, 1 simultaneous, eg, 1 after the other, it fails with a message on the * box ’ chan_sip.c:1976 retrans_pkt: Maximum retries exceeded on transmission sippuac for seqno 1 (Critical Response) and a message received by the client: Status 503: server error

here is the cmd line from the client:

sipp -cid_str sippuac -s 123 -d 5000 -sn uac -l 1 -m 1

Of course, if i try many simultaneous calls, it fails -

any ideas as to why ? or alternatively, scenarios & cmd line that work would be appreciated !

thanks for the help,


Anyone has ever used SIPP and could provide me with the scripts or command line used ?

many thanks,


any suggestions on how to test * ? even if other than sipp !