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Actual MWI packet information

We are running Unity with serial integration to an Intecomm E14 Millenium switch.<br><br>When Unity sends a lamp on command, Integration Monitor\View Raw Serial Data shows the following in italics:<br><br>OP:MWI_0007201!<EOT><br><br>Or for a lamp off command:<br><br>RMV:MWI_0007201!<EOT><br><br>Is this the actual data or is there a cryptic lamp code hiding behind what I see displayed in integration monitor? If there is a cryptic code, how can I see exactly what it is?<br><br>MORE INFO:<br><br>We have a situation where lamp on/off commands are being sent by Unity to the switch but the switch does nothing with the command. This is happening maybe 10% of the time and with 1800+ subscribers, it is causing us headaches. I am trying to eliminate all possible failure points related to Unity while our telephone guys are trying to eliminate all points related to the switch. Working as such, from both sides, we should meet at the problem soon (I hope).<br><br><br><br>David Stephens<br>Pepperdine University


Re: Actual MWI packet information

Those are the actual SMDI codes for lamp on and lamp off. You can send the same string with a terminal program and it should also activate and deactivate MWI. It's pretty easy to read, OP for on, RMV for off, followed by the :MWI then the SMDI extension number.

If Unity is sending the code but the switch isn't responding to the request, that's likely a problem in the phone system. If you have a loopback tester, you can do a loop back test to rule out a defective serial port or cable, but if it were a hardware problem you'd probably see the issue more frequently.

What you can do on the Unity is make sure you don't have any bogus lamp codes going out (disable MWI for virtual subscribers that don't have physical phones), and lower the number of retries if you see multiple instances of the same code going out each time. Some phone systems will flush their MWI queues if they get overloaded with lamp requests.

Oddly, I didn't see a place in the SA where you could set the MWI retry count (although you can do this for all the notification devices), but it's possible to modify the retries with the edit switch utility or in the switch file itself.

However, in this situation it sounds like the defective behavior is coming from the phone system, since Unity is doing its job by sending the lamp request.

Scott Morgan
Cisco Systems TAC


Re: Actual MWI packet information

Scott is correct. What you see there is the actual contents of the serial packet. There are a few "hidden" portions to the serial packet. They are the headers and trailers. most of the time, these are not printable ASCII characters, so they don't show up. Since you are doing SMDI, the headers and trailers are a combination of carriage-returns and line-feeds.

I can tell you that these are sent on all of your MWI packets and in the same manner in all of your MWI packets, so this could not cause an intermittent problem. If for whatever reason, the headers and/or trailers were incorrect, MWI would never ever work.

Steve Olivier
Software Engineer
Cisco Systems

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