NEC 2000 keeps dropping 4 digit calls

[TheRealTed]

I inherited a NEC 2000 that is connected to our 2400IPX via 8 channels (or it could be 6) of a T1 line. These channels are used for 4 digit dialing within our system. However this one switch alone in our collective constantly drops or often fails to connect 4 digit calls. If you watch the link light on the relevant card (24PRTB ? I'm not in front of the switch as I write this) in the 2400 you can watch it drop the link for about 4-5 seconds every 60 - 70 seconds. Just like clockwork.

Someone, somewhere told me that if the "D" Channel on the card was not set for a full 64bits but was for some reason set for 56 that it would/could cause this.

Is this true?

How do I check what the "D" channel is set for and on which side (NEC 2400 or the 2000)? Or both?

If it is set wrong how do I reconfigure it to be right.

Thanks

 

[PFD45]

Dch speed can definitely cause this.
Whenever I network a 2000 and a 2400 I have only had luck setting each side to 48k. The second 48k. There are 2.
What kind of card is in the 2000?

 

[TheRealTed]

I show (From what I've documented, I'm not in front of the switch right now) that the 2000 has a 24CCT / 24P card in slot 9.
Ted

 

[PFD45]

So it must be a 2000IPS.

Switch 2 should be 1,2,3,5 on.

On the 2400 side, IF it is a PA-24CCTA Card then SW18 (or 11B) leave 1~5 as is & 6,7 on and 8 off.

If you have other 2000's CCIS'ed to the 2400 then you might want to compare this to their settings before changing anything.

Be sure to write down the current config before changing anything.

 

[TheRealTed]

SW 17 is currently set with 1-7 ON and 8 OFF. Giving me 64 kbps on the Pad Pattern and making the Signal Channel #7 (which is what the lights indicate ).

SW 18 is currently set with 1-5 ON and 6 Off and 7 and 8 ON setting a Transfer speed of 56 kbps. When I tried setting it to 1 - 7 ON and 8 OFF (48 kbps transfer speed) the link light did not come on.

I have not yet been out to the 2000 side to see how it is set. I may get a chance to do that today. Or I may not depending on what else blows up.

 

[TheRealTed]

The only other setting for 48, 56 or 64 kbps that I see is switch 11 #3 and 4. I did not look this morning to see how my card was set.

 

[PFD45]

It sounds like you have the manuals. If not, let me know & I can upload the switch settings for those cards.

You will definitely have to do both ends simultaneously. They need to match.

I have only had luck setting SW18, 6&7 on and 8 off at the 2400 side giving 48k and at the 2000 side I set SW2, 1,2,3 & 5 to on (4=off).

This should put you at 48k at both ends.

If you can get 1 person at each end, do the 2400 first. The 2000 is notoriously finicky about syncing up.

 

[TheRealTed]

Currently the 2000 has Switch #2 set (Dip switch number from the RIGHT 1-8) 1&2 Down, 3 UP, 4&5 Down and 6,7,&8 UP

I've got my 2400 card manual but am not having any luck finding my 2000 card manual. How do you show that switch to should be set to set it to 48 kbps.

the 2400 is currently (Switch #18) 1-5 ON, 6 OFF, 7 & 8 ON for 56 kbps. I'm willing to try 1-7 ON and 8 OFF for 48 kbps but I want to make sure the card in the 2000 is set right at the same time.

Ted

 

[PFD45]

This should show the switch settings for the CCTA in the IPS2000.

I have only had luck setting SW18, 6&7 on and 8 off at the 2400 side giving 48k and at the 2000 side I set SW2, 1,2,3 & 5 to on (4=off).