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OPX port Hookflash Disconnect Question

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ar4479

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Jul 18, 2003
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Hi Guys,

I've got what is most likely a simple question for the Nortel gurus out there!

I am integrating some of my NextGen E911 equipment to a CS1000 via OPX ports, for the purpose of adding in "administrative lines" to the 911 calltaker positions.

The CS1000 connects to the PSTN via multiple PRIs.
Several DIDs point to the PRI and are then routed to the analog OPX ports, which deliver the calls to my Audiocodes FXO analog to IP gateways.
Outbound calls are also made from the FXO gateways, via the OPX cards and out the PRI.

Here is my dilemma:
When an incoming call is received down the PRI and in to the CS100, sent to the FXO and answered - if the far end disconnects, disconnect supervision is received (hookflash disconnect at 900ms) and processed correctly, and the call clears as expected.

When an outbound call is made from the 911 equipment, to the FXO gateway, out the OPX and sent to the PSTN via the PRI, when the far end disconnects, NO disconnect supervision is received. Hence, the call will hang open until the near end operator presses release and tears down the call manually.
(I know this doesn't seem like a big deal to most of us that would "hang up" the phone or reach over and press release when the call is complete, but to a 911 dispatcher who is doing 30 things at once, they are fighting back against having to look up and press release. The other issue is the lack of DS prevents them from dropping out of established conferences, since the lack of DS will hang the ports.)

The other feature that is available in the CS1000 and compatible with my Audiocodes Gateways, Dialtone Disconnect is not an option. There are a lot of hookflash xfers, and also a LD code prompt on outbound calls that is a "dialtone" that can't be changed.

I go back to my old days of doing voicemail integration to PBXs via analog ports - and wonder if the hookflash disconnect feature was ever intended to work on outbound calls. My thought was that Nortel designed it specifically for incoming calls, to prevent incoming calls from hanging the voicemail ports and leaving 30 minutes of a busy cadence recording.
Common logic says that when an outbound call is made and the call is complete, the near end HANGS UP. This shouldn't be an issue, but it is.
I know it sounds like a silly question... But I'm dealing with several layers of bureaucracy that are supporting the demand that the dispatchers don't want to reach over and press the release button on their phone.

Can anyone give a 100% definitive answer on the intended design of this feature? Should it work on both in/outbound calls?

(By the way, I've listened with a butt-set, and tested with a meter. The DS is definitely there on inbound calls and definitely not there on outbound calls).

Any help would be appreciated!!!

Thx
 
A few thing come to mind here.
1. What software release are you running?
2. What type of analog card are you using?

Nortel/Avaya makes a XOPS card that may do what you are looking for. It's an 8 port Off Premise Card and is programmed accordingly. If you look in the 7.5 NTP's Feature Guide under Off Premise Extension it explains it. Here's a little excerpt from the book.

The XOPS card requires a Main Distribution Frame (MDF) wiring installation plan similar to
trunks, rather than other line cards. Therefore, it will not be possible to interchange the XOPS
card with another line card without rewiring the connections, or adjusting the Terminal Numbers
(TNs) using service change.
The Classes of Service have been renamed to be consistent with industry standard terminology
as follows: OPX is now called OPS; and ONP is now called ONS.
The jumper settings must be set in accordance with OPS and ONS Classes of Service.
The XOPS hardware will support Answer Supervision through Battery Reversal or Flash Hook.
No software support is provided for any Loopback from Extended Network Card (XNET) or
XPEC to the XOPS line card.
The new XOPS line card uses B34 CODEC and Enhanced Extended Universal Trunk Card
(EXUT) trunk circuitry. Therefore, the downloadable Termination Impedance (TIMP)/Balance
Impedance (BIMP) combination parameter set, as defined for IPE EXUT, is likewise defined
for the XOPS. The usage of TIMP/BIMP implies a limited number of downloadable
combinations.
The XOPS is designed to work in North America using dynamic pad switching based on OPS
and ONS Classes of Service. The card functions in a Static Loss Plan Download environment,
but only the static levels associated with Analog Line Unit Short (ALUS) and Analog Line Unit
Long (ALUL) are supported. In these situations, only Class of Service Long Line (LOL) or Short
Line (SHL) has any meaning; OPS/ONS Class of Service of the unit is ignored.
As with the existing design, parameter download is not performed as part of enabling a
Superloop, but is done as part of an initialization, or enabling of a unit, card, or peripheral shelf.
Hardware is compatible with the EOS circuit switched
 
Hi KC,
Thanks for the reply.

Unfortunately, I'm not the PBX vendor - I'm the 911 equipment vendor tasked with making this integration work.
The only information that I can get from the PBX vendor is that it's an Off Premise card that is capable of "Hookflash Disconnect".
He is able to get it working for incoming calls, but not able to get it working for outbound calls.

His last comment to me, last week, was that he's not sure where to go next - and that this functionality may be by design.
I can see the logic in his "by design" statement - but I've got two customers that are beating me up bad!

I'm not going to be able to provide a lot of detailed info on the CS1000, other than what I've given, and what I've described in detail in my first post. I know it's not a lot, but it's all I've got to go on.

I'm hoping that someone can take those details and provide an answer to the inbound/outbound far-end supervision capability question.

Thanks
 
What about OPS FTR - ISP and OSP, Incoming and Outgoing Supervision, do these apply to this scenario?
Enable hook flash disconnect supervision with flash timer in 10 millisecond units. Enable battery reversal answer and disconnect supervision for outgoing calls with absolute and assumed answer indication.
 
The vendor indicated to me that when he did:
LD 10 - FTR - OSP, not only did we not get any hookflash disconnect on outgoing calls, but we also then lost hookflash disconnect on incoming calls. Seems like enabling OSP took us in the wrong direction.

I don't have 100% confidence in this vendor - that's why I'm seeking help here, from the world of experts!

Could he have not set an interaction properly between ISP and OSP?
All I'm looking for is a 900ms loop current interruption to indicate far end disconnect.
I've had him configure the ISP for 900ms, and it works great on incoming calls. Just no dice with any config on outbound calls.


 
According to the book there are also jumper settings on the card

The Classes of Service have been renamed to be consistent with industry standard terminology
as follows: OPX is now called OPS; and ONP is now called ONS.
The jumper settings must be set in accordance with OPS and ONS Classes of Service.
The XOPS hardware will support Answer Supervision through Battery Reversal or Flash Hook.
 
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