Test Numbers - To assist in setting up and testing PSTN-POTS, GSM and IP codecs

PSTN / GSM Test Line:
We maintain a test line so that our customers can check their codecs by calling in and although it is not guaranteed to be connected and should not be relied upon, if you call us, we can normally connect the correct device.

+44-(0)20-8579 7105

This is a PSTN line which can be connected to the following audio codecs: Please telephone using our Technical Support Number +44-(0)20-8579 2743 to check for availability and compatibility.

Comrex also maintains the following test numbers:
POTS/PSTN: +1-978-784-1700
ISDN: +1-978-772-9404

Vortex London UK: - normally a music radio station
Comrex Devens USA: - normally voice
Comrex Devens USA:

Comrex Traversal Server:
Click here for the current Traversal Server status