Drop Calls over E1/T1 with Adtran ESU 120e . . . .

[Anonymous]

To anyone happens with Adran ESU 120e drop calls ...

Users are into a call and after i don't know 2, 5, 8, 12, 23  min suddenly the call hangs ..   What can be .. ??

ESU 120e missconfiguration, differente transmission protocols from the carriers .....

Anyone ....  thks all ...

[Anonymous]

Thank you for your question. Has the ESU 120e been working fine previously? If so, then unless there was a config change on the ESU 120e or by the provider it’s not likely to a misconfiguration. What sort of voice traffic are you using? Is there a FXS module in the 120 or is the E1 passed out the DSX port to another device?

The first place you’ll want to check is the E1. On the front plate of the 120 you should be able to select Status. Take a look at the NI PERF RPTS and record the values you see here and reply to this message with them. Do the same thing for NI ERRORS. These values are the errors on the E1. Errors on the E1 can cause calls to drop sporadically. 

[Anonymous]

Hello ....

The only physicall change we made was this. We connect this ADTRAN 1200209LI 75Ohm /120ohm adapter on the DB15.

From there it goes to a E1/T1 card into a NEC PBX.

Before there were 4 pins/cables connected to the DB15 (without somekind of connector)

Values from NI PERF RPTS are

15 min / 24 hr

%AS = 100.0 /100.0

%EF = 100.0 / 99.9

ES = 0 / 68

BES = 0 / 0

SES = 0 / 0

DM  = 0 / 0

UAS = 0 / 0

Values from NI ERRORS are

CRC = n/a

LCV = blank/empty

FER = blank/empty

Thks in advance ..

[Anonymous]

Thanks for the photo, it gives me a good idea of how things are connected.  The adapter is going into the 0.2 drop port which is connecting to your PBX.  Under Status, go to Port Status and look at Port 0.2.  This should show CRC, BPV, SLIP and FER errors.  Let me know if any asterisks are displaying here.  When you check in the PBX, does it give you any indication of why the call dropped?

[Anonymous]

Hello .... under Status / Port Status / Port : 0.2 Drop PT / Drop Errors (all four are blank, no asterisks)

CRC

BPV

SLIP

FER

hmmmm ... because on the drop calls there's not an standard time when they drop, i mean; it could be at 2 min ant the call drop

or even a user could be on a call 1hr :45min and no drop ...

monitoring the PBX remotely we got this results .. 

Communication Error recovered between Main Site and

Remote Site

(Remote Site = 01)

Data = (01 FF FF FF FF FF FF FF)

DTI line failure.

Power Failure Kind : AIS error

Data = (F3 FF FF FF FF FF FF FF)

Kind regards ...

[Anonymous]

Thanks for the information.  The AIS alarm is interesting, that's normally a physical level alarm that indicates the T1 is down.  The ESU will not generate an AIS alarm, it would have to be passed through the ESU from the outside T1, but we didn't see any errors on that T1 that would indicate an alarm.  Can you bypass the ESU and plug the T1 straight into the PBX?  I can't tell from the photo is there is a data connection as well as voice, but this would be the best way to verify if the problem is on the T1 or the Adtran.

[Anonymous]

Let me share how its connected.

We have at RX / TX connectors connected a PairGain equipment for the E1/T1 circuit.

We have at Drop Port 0.2 the E1 BNC to DB-15 Adapter both on open earthed to the sides and this goes to the E1/T1 card on the NEC PBX

We have under those two, two cables going to a Cisco Router.

Im lost when you told me to bypass the ESU and plug the T1 straight into the PBX ? 

I can take a photo on how its the E1/T1 card into the PBX .... if that helps ...

Thks in advance.

[Anonymous]

Thanks  for the photo.  Removing the ESU and hooking straight to the PBX would be a short term test, for that time the data connection would be down.  The AIS alarm shown is not something that would come from the ESU, so with the ESU eliminated from the connection we're trying to determine if the problem persists or not.  Based on the photo, you have coax for the E1 going into the ESU and going out from the ESU to the PBX, so it should be possible to connect the E1 directly to the pbx.  If the problem persists then we've eliminated the ESU as the source of the problem. 

If the problem goes away without the ESU in the connection or if you have additional questions on this, please feel free to email us at support@adtran.com. 

[Anonymous]

Since there were no further questions we flagged this post as “assumed answered”.  Please feel free to mark any Correct or Helpful answers that assisted you.  If you still need assistance please let us know and we would be more than happy to continue working with you.

[Anonymous]

Hi ...just yesterday we got both ISP doing complete test to the E1 / T1 circuit     .....   we got this answer from AT&T

Both ends have been stressed tested, with clean test results.  I would of suggest have your  vendor prioritize the voice over data into your router, if calls are a priority.

Thanks

AT&T Associate Tech Support Network Analyst

... Today will arrive NEC tech to do test beetween PBX and MUX ...    i will keep you posted . !!

Meanwhile calls still drop ... 

[Anonymous]

It sounds like ATT is assuming the voice traffic is VOIP.  The ESU is MUXing out the channels from the T1 for the data and the voice so there is no priority to set on the ESU.  I look forward to seeing what the tech finds on the PBX side.  Hopefully we can verify if it's seeing AIS alarms.

[Anonymous]

NEC tech change the E1 / T1 card into PBX .... We clear the alarm history into ESU ....    and start from there,

we invite user to make calls and if any drop, they will let us know so ASAP.

ALL GOING SMOOTH AND PERFECT ....  and suddenly ...  CHAOSS

Calls drop, over and over again ...

Into ESU at  Status / View History  we got this results

1:26pm - 04/03 - 0.2 Remote Alarm

1:26pm - 04/03 - 0.2 Remote Alarm Clr

1:30pm - 04/03 - 0.2 Remote Alarm

1:26pm - 04/03 - 0.2 Remote Alarm Clr

1:30pm - 04/03 - NI Frame Slip

1:30pm - 04/03 - NI Frame Slip Clr

1:40pm - 04/03 - 0.2 TS16MF Loss Clr

2:11pm - 04/03 - NI Frame Slip

2:11pm - 04/03 - NI Frame Slip Clr

2:11pm - 04/03 - 0.2 Remote Alarm

2:11pm - 04/03 - 0.2 Remote Alarm Clr

2:18pm - 04/03 - 0.2 Remote Alarm

2:18pm - 04/03 - 0.2 Remote Alarm Clr

2:18pm - 04/03 - NI Frame Slip

2:18pm - 04/03 - NI Frame Slip Clr

2:43pm - 04/03 - 0.2 Remote Alarm

2:43pm - 04/03 - 0.2 Remote Alarm Clr

2:43pm - 04/03 - NI Frame Slip

2:43pm - 04/03 - NI Frame Slip Clr

3:07pm - 04/03 - NI Frame Slip

Toughts ...

[Anonymous]

A remote alarm on the 0.2 suggests there was an alarm on the line going to the PBX.  Did the tech see any errors on the PBX side?  When it was going smoothly, were calls going through with no problem?

If you have no bypassed the ESU yet for testing purposes, I'll recommend it again.  Based on the photo both sides of the connection use coax cables and since the ESU will just be muxing out certain channels for the PBX, the PBX should be able to make calls on the E1 when it's plugged in directly.

[Anonymous]

NEC Tech guys get and his program, this report ...

(Remote Site = 01)

Data = (01 FF FF FF FF FF FF FF)

DTI line failure.

Power Failure Kind : AIS error

Data = (F3 FF FF FF FF FF FF FF)

Calls were made from around hour and half and not problems at all. Suddenly drops calls.

I talk with NEC tech guy regarding doing that. Bypass ESU and he don't recommend it.  He explain to me about signaling differences beetwen US and MX.

and thats why he doesn't recommend it.

What about this errors ....

0.2 TS16MF Loss Clr  &   NI Frame Slip   mean something important for this kind of problems .. ???

BTW and going crazy right now .....

Do you think  if i change the 2 COAX patch cord going from PBX into ESU, could make any significant change ....I mean the actual ones are very ... thin .....

[Anonymous]

It could not hurt to replace the coax cables, but I would not expect cables to lead to an AIS error.   But it could relate to a power failure and the AIS looks like it's coming from the PBX.

The ESU muxes out E1s, so the signaling it likely to be the same on both sides.    You should be able to look under Config in the ESU and check the Network (NI) and Port (0.2 Drop) and see if the  NFAS word, CAS/TS16, and CRC-4 are all set the same.  If they are the same for both ports, then the E1 can connect to the PBX.

Take a look at the NI Perf Reports and NI Errors the next time the problem comes up, and the   Port Status 0.2 as well. 

[Anonymous]

We change the 2 COAX patch cords from the E1 BNC to DB15 Adapter to E1 card into PBX..

Also we change into Config / Network (NI) / Interface from 120 Ohm bal to 75 Ohm Bal.

But i got a question ... regarding E1 BNC to DB-15 Adapter ....

Right now both dip switches are down ....  so we match that with the change made below.

Do this change could mean anything for the problem we have ....??

[Anonymous]

Just staring watching at the computer room the ESU, suddenly i got alarms into CSU and DSU / DROP

Into Status / Port Status / Drop Errors

I got asterisk into BPV / SLIP / FER the one named CRC its blank.

[Anonymous]

What alarms do you see in the alarm history? And on the Network side do you see errors under NI Perf Rpts?  I would normally expect a hardware issue with the ESU to show persistent errors or alarms, not for it to come and go.  The drop port was showing Bipolar Violations, clock slips, and framing errors.  So if we had alarms on both sides of the ESU, we want to see where we were receiving an alarm and where we were transmitting an alarm.

I'm not sure about the dip switches, are they on the adapter?  The ESU 120 has no dip switches, so I'm not sure what a change in the switches would represent. 

[Anonymous]

The dip switches are into the adapter, on both sides.

At the alarm history we got

- 0.2 Remote Alarm

- 0.2 Remote Alarm Clr

- NI Frame Slip

- NI Frame Slip Clr

Under NI Perf Rpts no errors at all.

Could be all this behavior at hardware failure at the ESU ?

[Anonymous]

So, what we're seeing at the time the trouble comes up is an alarm from the PBX.  Based on the information from the PBX vendor, there is an AIS alarm at that time. It could be a hardware issue with the ESU.  It could also be a hardware issue with the PBX.  The best way to test that will still be to plug the E1 straight into the PBX for testing purposes and see if the the problem persists or goes away.