Hello All, Here's the problem, I have happily set up several Asterisk servers to offer commercial service SIP using a VoIP provider in the UK (Magrathea), they use SER/Cisco to provide the service on a public IP address - till now we have used Asterisk to connect clients on private IP's with Asterisk doing the required conversion between public and private IP's. The current issue is that we have recently agreed to support ShoreTel PBX's with their new SIP trunk feature, and in staging the first install we have found that certain features (blind transfer) require support for both Refer and Refer Replace - which are not supported by the current VoIP provider SER config. So the challenge is to quickly work out the possibility of adding a SER setup in-between the ShoreTel PBX and the VoIP provider SER unit. The intent of this SER setup is to both allow for NAT - EG use private IP's for the ShoreTel system and public for the VoIP provider, as well as ensure that the local SER server supports the required Refer commands to allow the ShoreTel PBX to be able to offer blind transfer support. My problems are: a) IpTel php bbs seems to be down? b) Very short timetable to deliver the working solution - 1 week. c) Steep learning curve with SER - particularly as some (most) of IpTels web site is down? Can any one offer guidance on whether my proposed solution will work and share any tips on problems I should be aware of? If any one is interested in taking this on as an Easter project for minor commercial reward - email me off list (magnus at mcomwifi dot net) If this is the wrong list for this type of thing - Apologies