Ds1 board Protocol:
o A = Custom or NI1 National. This is typically used when your T1 comes out of
an AT&T 4ESS Central Office.
o B = NI2, and is typically used when your T1 comes out of a 5ESS Central Office
This is the only protocol capable of giving the customer NAME and number
Caller ID. You always prefer this protocol if the vendor can provide it!
ISO/ETSI QSIG. Also used for SBS signaling trunks.
o C = Nortel Custom. This is a new protocol, and is sometimes used when your T1
comes out of a Nortel DMS Central Office. RARE. ETSI public network.
o D = NI2 ECMA QSIG European Computer Manufacturer's Association (ECMA) QSIG
private network (supports only Name Identification and Additional Network
Feature Transit Counter (ANF-TC))