SIP Trunk CM to IP Office

[hdbeavis]

Does anyone know if I have to have an SES Server to create SIP Trunks between an IP Office and a Communication Manager Server. I am thinking I do but have not found any documentation as of yet either way. Thanks

 

[Midstream]

I think you do. I was told once that you only need the SES for border security and tried to set up a SIP trunk between my CM4 and my Call Manager 6 without having an SES. No dice. Had to setup a H.323 trunk group, which works pretty well.