Dual integration to Octel using VG248/CCM/NEC problem

Unanswered Question
May 31st, 2007
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This is an FYI for those folks using a legacy voicemail on VG248 using Callmanager and NEC MCI serial integration.

The VG248 has an ASYNC1 port which is attached to the serial port on the Octel. The ASYNC2 port is attached to the MCI serial port on the NEC. Call information packets are relayed to the Octel from the NEC and generated on the VG248 from the CCM. MWI packets from the Octel are sent both to NEC and to CCM (converted to SCCP by VG248.

When you hook up the NEC to the ASYNC2 nothing happens, no packets are sent. If you attach your PC to the NEC and run a terminal program you see packets being sent.

Here's why:

NEC 2400 and 2000 PBX require the following RS232 signal lines to be active (> +5 volts) on the 25 pin connector side:

4 - RTS

5 - CTS

6 - DSR

8 - DCD

20 - DTR

The async2 port on the VG248, even though it is acting as the "host" terminal side does not drive the RTS or CTS lines to an active state.

In addition the RJ45 connector on the VG248 does not even have the DCD pin implemented.

Without all the above lines active the NEC PBX sees the host end as not ready to recieve data so no packets are sent.

The solution is to create a 25 pin F/M adaptor which is basically a "straight thru"

cable (pin1 to pin1, pin 2 to pin2 etc...), with the DTR pin jumpered to either the RTS or CTS

to force both on.

I would think that if the VG248 is sold to support the NEC, Ericsson and SMDI serial protocols, (which it does not - without the above workaround) some thought would be given to actually detailing the RS232 requirements in the Cisco documentation.



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