[cisco-voip] T-CCS problems with Siemens Hicom CORNET

[Pilkington, Christopher J.]

I'm attempting to get two Siemens Hicom 300E PBXes to talk using
the proprietary Siemens CORNET networking protocol via a pair
of 3845 routers connected by a GRE-over-IPSec-Transport-mode
tunnel over a point-to-point DS3.

Hicom --T1--> 3845 --gre tun--> 3845 --T1--> Hicom

We are carrying the B channels of the T1 using g711ulaw and
the D channel using the clear-channel codec.

I see all the ports come up successfully from the 3845 routers'
perspective.  The PBXes also see the T1 as up.  However, they have
difficulty getting the D channel to come up.

One of our Siemens techs said that it is because the T1 itself
is up before the D channels can actually pass traffic.  We were able
to get one of the T1s to work by plugging in the T1 to each side
exactly at the same time.  However, this was inconsistent.  But once
the D channel comes up, everything is fine -- calls go through and the 
Siemens Hicom is none the wiser that it's not using a "real T1."

The previous environment is circuit emulation over ATM.  When we
rolled back to that ATM-based environment (non-Cisco) the circuits come
up with no problem.

Has anyone experienced anything similar?  Some relevant config snippets
from one side are below.  The other side is identical, except the
numbers are complimentary and no answer-mode.

controller T1 0/0/0
 framing esf
 linecode b8zs
 ds0-group 0 timeslots 24 type ext-sig
 ds0-group 1 timeslots 1 type ext-sig
 ds0-group 2 timeslots 2 type ext-sig
[...]
 ds0-group 23 timeslots 23 type ext-sig

voice-port 0/0/0:0
 no vad
 timeouts call-disconnect 3
 timeouts wait-release 3
 connection trunk 1013000 answer-mode
!
voice-port 0/0/0:1
 timeouts call-disconnect 3
 timeouts wait-release 3
 connection trunk 1012001 answer-mode
[...]
voice-port 0/0/0:23
 timeouts call-disconnect 3
 timeouts wait-release 3
 connection trunk 1012023 answer-mode

!
dial-peer voice 1053000 pots
 destination-pattern 1053000
 port 0/0/0:0
!
dial-peer voice 1052001 pots
 destination-pattern 1052001
 port 0/0/0:1
[...]
dial-peer voice 1052023 pots
 destination-pattern 1052023
 port 0/0/0:23
!

dial-peer voice 1012000 voip
 description Bearer Channels to
 destination-pattern 1012...
 session target ipv4:10.10.10.10
 codec g711ulaw
!
dial-peer voice 1013000 voip
 description D Channels to
 destination-pattern 1013...
 session target ipv4:10.10.10.10
 codec clear-channel
!

Thanks,
Christopher