Hi Team, Working on Kamailio setup with IMS components(P-CSCF, I-CSCF, S-CSCF). Assigned IP's: hss/server-10.0.0.9 P-CSCF-10.0.0.10 I-CSCF-10.0.0.11 S-CSCF-10.0.0.12 Here tried to send an REGISTER request from Boghe IMS client, the register request should go from P-CSCF to I-CSCF, here P-CSCF - I-CSCF communication is not happening but I could able ping. One more thing observed from logs here is REGISTER request don't have username (username is not there in request line), Execution log: 0(1338) DEBUG: ims_usrloc_pcscf [usrloc.c:106]: get_alias_host_from_contact(): no alias param Please find attachment of Zone file, SCSCF.xml, Diameter.xml, ICSCF.xml and tcpdump. Any changes/suggestions would be very helpful. Regards, Sainath The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com