problem with a digital FCT

[vuser1]

Hello, I´m trying to connect a digital FCT connected to MD by a TLU79. I´ve programmed the route like another basic ISDN route that is working now in another PBX.
The problem is that before some time and if you use this channel, suddenly you can´t make calls troughout the FCT. I only have a wrong warning in my PBX: 303 Data link alarm.
Have you ever used this digital FCT? Do you know where I have the problem?
Thank you very much. I´m waiting for your answer

 

[rfpui]

Data link alarm - faulty data link layer

Fault code description

The TLU-board has discovered an error on the data link layer and has informed layer 3. Layer 3 has analysed the type of error and according to type some action is performed.

Possible actions are, request link restart, send alarm and block board. Assumption is that cause for alarm will expire after a while. The alarm will be acknowledged when the TLU-board receives information from the other side that the data link layer is in right state. Layer 3 will be informed by primitive that the data link is established again.
[tt]
ADD INFO 1: Pointer to the interface.

ADD INFO 2:
0, G fault, Unsuccessful data link establishment

1, H fault, No DL (Data Link) -RELEASE acknowledgement

2, Maximum retransmit count exceeded.

3, J fault, Invalid received sequence number.

4, K fault, Frame reject response.

5, A fault, Not expected supervisory response.

6, B, C, D, E fault, Not expected UA (Unnumbered Acknowledgement or DM (Disconnected Mode) response.

7, F fault, SABME (Set Asynchronous Balanced Mode Extended) from peer received.

8, Q fault, Blocking received.

9, R fault, DM (Disconnected Mode) response received.

10, I fault, No response on RR (Receiver Ready) or RNR (Receiver Not Ready).

11, O fault, Received information field > N201 (260 Octets)

12, L fault, Undefined control field.

13, N fault, Received frame with incorrect length.

14, M fault.

15, P fault, N2X4, Maximum number of retransmission of RNR frames exceeded.

18, TEI Removal received.

26, TEI Removal received.
[/tt]

 

[rfpui]

Sorry I send copy from alex without my opinion
Version of your MD please
And RODAP:ROU=…..;
I never connect digital FCT to MD but I connect more other devices using digital links.
Very often I has this alarm 303.
And often was a problem with devices status, which one is a master and which one slave.
Now I send you copy from alex how to interpret alarm 303

 

[vuser1]

Version of MD is BC9
And RODAP:ROU=…..;
VARC VARI VARO FILTER
H'00001814 H'04C00000 H'464100A0 NO
I´ve listened something about master and slave. The FCT has to be always master and it gives the clock to MD. This give me an alarm: 274 DIGITAL TRUNK, CLOCK MALFUNCTION. It is class 1 alarm.
Thank you very much

 

[whosrdaddy]

2 things :

- what brand of fct are you trying to connect to the md110?
- is the MD110 already synchronized to an external source? (verify with SCEXP)
- normally, the md110 has to be clock master because
an fct CAN't give clock (its a GSM, so no clock), UNLESS it is synchronized by an external BRA (which would be dumb because we can synchronize via the pbx).

a normal clocking scheme would be

provider ISDN PRA/BA ----> MD110 ----> digital FCT
clock clock

if you want to create problems (like slip and so on) do this :

provider ISDN PRA/BA ----> MD110 <---- digital FCT
clock clock

anyway I would program these parameters :

varc : 00000014
vari : 00000000
varo : 06310000 md110 is master
varo : 06410000 md110 is slave

greetings

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