T1 down/down - new turn up

Unanswered Question
Jul 24th, 2009

at various speeds. The LEC is clean, the ISP can remote loop my router -after finding loops in their network-, but my end shows down/down their end shows up/down. The router works great in the old ckt(we are migrating to new ISP)but not the new isp ckt. I've went so far as changing out the T1Wic and I still show down/down. Keep in mind I've done over 70 turn ups with the guy and I know his configs are solid and I've checked mine also. Look at the reliability of his interface, it should be 255/255 at one point is was 147/255 and when we tried the turn up it was 188/255 and fluctuating.

Below is a show int from the ISP PE

Serial4/0.12/2:13 is up, line protocol is down

Hardware is Channelized Sonet/SDH to T1/E1

Internet address is X.113.239.X/30

MTU 1500 bytes, BW 256 Kbit, DLY 20000 usec, rely 247/255, load 1/255

Encapsulation PPP, crc 16, loopback not set

Below is my configs-

interface Serial0/0/0

bandwidth 256

ip address X.113.239.X 255.255.255.252

ip accounting output-packets

encapsulation ppp

service-module t1 timeslots 1-4

service-module t1 fdl both

end

sh serv

Interface Serial0/0/0

Module type is T1/fractional

Hardware revision is 1.2, Software revision is 20070718,

Image checksum is 0x4144A7, Protocol revision is 0.1

Transmitter is sending remote alarm.

Receiver has loss of frame,

Framing is ESF, Line Code is B8ZS, Current clock source is line,

Fraction has 4 timeslots (64 Kbits/sec each), Net bandwidth is 256 Kbits/sec.

Last user loopback performed:

line loopback

duration 00:00:30

Last module self-test (done 1d06h): Passed

Last clearing of alarm counters 1d06h

loss of signal : 0,

loss of frame : 1, current duration 1d06h

AIS alarm : 0,

Remote alarm : 0,

Module access errors : 0,

Total Data (last 96 15 minute intervals):

3063065 Line Code Violations, 98208 Path Code Violations

2 Slip Secs, 52 Fr Loss Secs, 86355 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 2147418112 Severely Err Secs, 86400 Unavail Secs

Data in current interval (345 seconds elapsed):

7847 Line Code Violations, 1023 Path Code Violations

0 Slip Secs, 0 Fr Loss Secs, 345 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 345 Unavail Sec

sho int s0/0/0

Serial0/0/0 is down, line protocol is down

Hardware is GT96K with integrated T1 CSU/DSU

Description:

Internet address is X.113.239.X/30

MTU 1500 bytes, BW 256 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation PPP, LCP Closed, loopback not set

Keepalive set (10 sec)

Last input 1d06h, output 1d06h, output hang never

Last clearing of "show interface" counters 1d08h

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: weighted fair

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/1/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 192 kilobits/sec

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

27 packets input, 1914 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 7 giants, 0 throttles

1488 input errors, 1488 CRC, 593 frame, 343 overrun, 0 ignored, 1135 abort

51 packets output, 714 bytes, 0 underruns

0 output errors, 0 collisions, 3 interface resets

0 output buffer failures, 0 output buffers swapped out

6 carrier transitions

DCD=down DSR=up DTR=up RTS=up CTS=down

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Giuseppe Larosa Sat, 07/25/2009 - 12:21

Hello Eric,

you and your provider need to verify also the SDH network:

the ADM and RED: not all of these devices are able to support fractionary E1 or T1.

Some RED are able to support E1.

another aspect to check is the position of the timeslots:

you have configured the first 4 timeslots but the counterpart is using channel-group 13 of logical E1 taken in a channelized SDH OC-3.

It is likely that the 4 timeslots on the other side have different and higher numbers.

Hope to help

Giuseppe

pcameron Sun, 07/26/2009 - 05:05

Your physical layer is completely hosed -

3063065 Line Code Violations, 98208 Path Code Violations

2 Slip Secs, 52 Fr Loss Secs, 86355 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 2147418112 Severely Err Secs, 86400 Unavail Secs

Data in current interval (345 seconds elapsed):

7847 Line Code Violations, 1023 Path Code Violations

0 Slip Secs, 0 Fr Loss Secs, 345 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 345 Unavail Sec

When the link is actually passing data, there are a lot of layer 2 errors -

27 packets input, 1914 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 7 giants, 0 throttles

1488 input errors, 1488 CRC, 593 frame, 343 overrun, 0 ignored, 1135 abort

Very first thing you can do is put in a T1 loopback plug using the following pinouts -

1 ---|

2 ---|---|

4 ---| |

5 -------|

This will loop TX to RX on the line side of the T1 interface. If this runs cleans the issue is external to the router. You may have a framing and linecode mismatch - perhaps try 'linecode ami' and 'framing sf'

Another common reason why we see these kind of errors is the SP has provisioned the T1 for CAS voice operation, not data. The ABCD bits in timeslots 6,12,16 and 24 mess up data framing.

DialerString_2 Mon, 07/27/2009 - 17:02

we verified that the framing and linecode settings are correct. I tried changing the timeslots to different slots. I'll figure this out tomorrow with the ISP and once I do, I'll reply back to this thread.

DialerString_2 Tue, 07/28/2009 - 12:05

We go this working. Come to find out it was a bad pair on the LEC side. thanks for your input guys.

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