[solved] Call says "answered" but keeps ringing then drops

The order of chan_dahdi.conf operations is the key

Success:

[channels]
switchtype = national
signalling = pri_cpe
group = 1
usecallerid=yes
context = from-pstn
channel = 1-23

recognizes "context "

Fail:
[channels]
switchtype = national
signalling = pri_cpe
group = 1
usecallerid=yes
channel = 1-23
context = from-pstn

not recognize "context "


scenario

A) 1 out of every 20 calls

B) The cli says “answered” but the caller hears ringing. It is not actually answered

C) The call drops without going to the programmed voicemail for a user.

Version - Asterisk 1.8.15.0

chan_dahdi.conf

[trunkgroups]
hidecalleridname=no

[channels]
switchtype = national
signalling = pri_cpe
group = 1
usecallerid=yes
channel = 1-23
context = from-pstn

Hmm, lol?

Assuming that the answered refers to the dahdi side, you need to ask your network operator, as answer indications over PRI are unambiguous. Are you sure that ringback is coming from the network and not the destination PABX?