Caller ID showing up as coming from the Netherlands

[ralph]

SIP Trunks.
3300 MXeIII Release level: 8.0 SP3 PR3

I have an issue with a Chicago customer.
Their area code is 312.  The international dial code for the Netherlands is +31
When they call out, some cell phones report the call as coming from the Netherlands so they think it's a spam call and ignore it.
Of course the carrier says that we are causing the problem.
I can't think of anything that I would be doing that may cause the carrier to flag it as a call from the Netherlands.

Any thoughts?

Ralph

[johnp]

I would guess the carrier is using sip. Nothing the PBX is doing IMHO. Maybe they should present caller id as +1312

[lundah]

SIP trunks? Check the Signalling and Header tab of the SIP Peer Profile, and turn off the E.164 options.