Thanks for respond. I just have used forward() based on RURI. got 0(2558) ERROR: <core> [msg_translator.c:1835]: ERROR: build_req_buf_from_sip_req: out of memory 0(2558) ERROR: <core> [forward.c:601]: ERROR: forward_request: building failed 0(2558) WARNING: <core> [receive.c:211]: WARNING: receive_msg: error while trying script With maxfwd it works like a charm. http://paste.ubuntu.com/1204093/ 2012/9/12 Daniel-Constantin Mierla &lt;miconda(a)gmail.com <mailto:miconda@gmail.com>> Hello, On 9/11/12 1:12 PM, Anton Kvashenkin wrote: Hi, List. I'm using sipsak to fire some predefined sip message with Max-Forwards: header equal 0 to test mf_process_maxfwd_header function. I'm doing this exclusively for learning purpose. As far as we know, this exported function from maxfwd module services only for adding Max-Forwards header, decrement or detect Max-Forwards: 0 header to prevent loops. So, my question guys, how can I create this loop in my lab, with two proxies for example? What message should I craft? what kind of message are you looking to craft? Looping from one proxy to another can be achieved with t_relay("_the other proxy address_") function from tm module. Cheers, Daniel -- Daniel-Constantin Mierla - http://www.asipto.com http://twitter.com/#!/miconda <http://twitter.com/#%21/miconda> - http://www.linkedin.com/in/miconda Kamailio Advanced Training, Berlin, Nov 5-8, 2012 - http://asipto.com/u/kat Kamailio Advanced Training, Miami, USA, Nov 12-14, 2012 - http://asipto.com/u/katu