Hi, Hope someone can help me. I have a fairly bad NAT situation. Clients are behind NAT and SER is behind NAT. The idea is that the clients will register to the public address which is assigned to my router and I have enable port-forwarding to send the packets onto the pc running SER listening on 5060. This situation worked when clients registered with Asterisk but I would rather them to register with SER and just use Asterisk for voicemail etc. My config is like the default except the nathelper and mysql modules are loaded. I have looked at the following websites but all the configs are very different and use different rtp proxys..I am also confused as to how much configuration is required to accommodate nat http://lists.cs.columbia.edu/pipermail/sip-implementors/2004-February/ 006179.html http://voip-info.org/wiki-SER+example+NAThelper Could someone give me an idea of how the script should be modified, what else must be installed (rtp proxy wise)or any ideas as to why my clients cant register?....Im presuming its nat... Thanks a million, Aisling. -------------------Legal Disclaimer--------------------------------------- The above electronic mail transmission is confidential and intended only for the person to whom it is addressed. Its contents may be protected by legal and/or professional privilege. Should it be received by you in error please contact the sender at the above quoted email address. Any unauthorised form of reproduction of this message is strictly prohibited. The Institute does not guarantee the security of any information electronically transmitted and is not liable if the information contained in this communication is not a proper and complete record of the message as transmitted by the sender nor for any delay in its receipt.