Business Phone Systems

Previous Thread
Next Thread
Print Thread
Rate Thread
Page 2 of 3 1 2 3
Joined: Feb 2009
Posts: 27
Member
Offline
Member
Joined: Feb 2009
Posts: 27
The most important thing to remember when troubleshooting an HDSL2/4 facility is that it is an analog transport facility for the digital DS1 payload. Hence the TC-PAM line encoding. BERT testing with traditional digital stress patterns will help isolate trouble to the circuit packs(HLU,HRU,HRE)themselves or to equipment or wiring on either side of the HDSL span, but it will not just cause errors on the HDSL facility because you send different patterns of 1's & 0's. If you are infact working with Adtran HDSL4 technology on this trouble their should be a wealth of PM Data info on the facility to help you troubleshoot. SNR margins & Attenuation between the network elements on the span, splice detector/histogram, facility and alarm history, DSX-1 and DS1 performance data, and HDSL span performance data(ES,SES,UAS)can all be used to help isolate the trouble without actually taking the circuit down

Atcom VoIP Demo
VoIP Demo
Joined: Feb 2009
Posts: 27
Member
Offline
Member
Joined: Feb 2009
Posts: 27
If you are a Special Services technician with an ILEC you should have access to a remote testing system that you can use to retrieve all pm/provisioning/alarm info off of the Adtran HDSL4 facility thru the Facility Data Link/T-SCAN feature built into the HDSL electronics.

Joined: Aug 2010
Posts: 11
Member
OP Offline
Member
Joined: Aug 2010
Posts: 11
once again, it's not an H4 circuit, it's an Adtran HDSL 4 wire circuit. No Tscan. The 1rst adtran hdsl technology. The end smartjack is called an HTUR. I could swap to H4 technology but the CO has no spare office repeaters, atleast they didnt 2 weeks ago. I've since had the Spare converted to be the main. Now the circuit that was giving me problems is a spare I need to fix, but my tech log has about 20 non-measured tickets I need to get to when I get time (HAHAHAHA Spare time...WTF is that???)

Joined: Jul 2003
Posts: 766
SST Offline
Member
Offline
Member
Joined: Jul 2003
Posts: 766
You need to have the testing tech segment the circuit. Testing the whole path end to end will not tell what item is causing the trouble. I'm betting there is a bad low speed card or DCS in the path. QRSS will usually ID bad cable. Since QRSS passes I'm betting on electronics as the culprit.

1:7 (also written as 1-in-8) – An 8-bit pattern that contains a single one and is used primarily to
test clock recovery and may be used framed or unframed. When transmitted unframed the pattern
has a maximum of seven zeros, and the pattern will not force the B8ZS line code. When
transmitted framed, framing bits can force the maximum number of consecutive zeros to eight,
and the pattern will invoke the B8ZS code in interfaces optioned for B8ZS

ALL ONES – An unframed pattern that has ones in all payload bit and frame bit positions. It
causes transmitter circuitry to consume the maximum possible power. In a T1-Carrier span with
line- powered repeaters, this pattern will verify that the dc power is regulated correctly. An All-
Ones pattern is the same as an Alarm Indication Signal (AIS) or “Blue Alarm,” which is sent
forward by an interface that has lost its input signal. It will never invoke the B8ZS line code.
This pattern only should be used in isolated segments of a transmission system and not in
transmission chains; otherwise, it may produce unpredictable results.

ALL ZEROS – A framed pattern having all payload (non-framing) bit positions set to zero. The
pattern is used to verify that all interfaces in a transmission chain are optioned for B8ZS. If any
interface in the chain is incorrectly optioned for AMI, it will fail immediately because no pulses
are available for clock recovery.

Joined: Jul 2005
Posts: 860
Member
*****
Offline
Member
*****
Joined: Jul 2005
Posts: 860
Quote
Originally posted by phoneman69:
I could swap to H4 technology but the CO has no spare office repeaters, atleast they didnt 2 weeks ago.
Which Telco do ya work for? With that part of AR there's a 50/50 shot your "no spare card issue" can be cleared up right here. wink ... PM me if you don't feel comfortable stating your employer here in an open forum.


-----------------------
Bryan
LEC Provisioning Engineer
Cars -n- Guitars Racin' (retired racer Oct.'07)
Joined: Aug 2010
Posts: 11
Member
OP Offline
Member
Joined: Aug 2010
Posts: 11
AS for the patterns that fail, its not my choice. It's the Full Maintenance NI test that we as outside techs must use to close out a trouble report. Its consist of 5 min qrss, like 2-3 min 1n8, 2 min all 1's and 2 min all 0's....as far as what telco I work for, lets just say it's probably the biggest in America.....

Joined: Jul 2005
Posts: 860
Member
*****
Offline
Member
*****
Joined: Jul 2005
Posts: 860
The first generation of Adtran HDSL was a big improvement over conventional DSX1 spans but the older technology can get a little flakey at time… Since you
from within the bowls of the death star, I can’t directly help ya, but here’s what I’d do

Your SSC tester should be able to turn in a ticket (TFAS?) to your CPC requesting a redesign from the first generation HDSL to HDSL4. Doing it on an internal order (aka bureau CLO or aka B-CLO) should generate a PICS ticket to send new cards to the C.O. you’re working out of. I’m sure things have changed since I was there, I know the TFAS process has come along since I left their CPC.


-----------------------
Bryan
LEC Provisioning Engineer
Cars -n- Guitars Racin' (retired racer Oct.'07)
Joined: Feb 2009
Posts: 27
Member
Offline
Member
Joined: Feb 2009
Posts: 27
Once again???....Your original post didn't specify whether you were working on legacy 2B1Q 4-wire HDSL or HDSL4, only that it had a doubler/range extender in the route, which meant it had to be a 4-wire technology. The Adtran HDSL technology registers a lot of pm data on the HDSL span & DS1 payload inbound on either side of the HDSL carrier. You haven't posted any of that information. Also, is this circuit working directly off of a repeater shelf in the serving CO straight to the cable pairs or is it working off a multiplexer at a remote terminal in the field??....You haven't posted enough info on the circuit build/design for anybody here to help you. Everybody FYI!!!...CART(craft-access-to-remote-testing)is the semi-automatic test application he is using. It is integrated with ATAS(Automated-Testing-and-Analysis-System)to provide remote field testing

Joined: Feb 2009
Posts: 27
Member
Offline
Member
Joined: Feb 2009
Posts: 27
The CART full maintenance ni test he mentioned initiates an automated test sequence thru the ATAS system and loops & runs QRSS,1 in 8,all 1's & all 0's to the Network Interface Unit chosen(A-end or Z-end of the circuit)at the start of the test from the closest digital test point(DTAU,DACS,etc.)to the niu being tested. A single bit-error on any pattern during the test will cause the entire test to fail

Joined: Feb 2009
Posts: 27
Member
Offline
Member
Joined: Feb 2009
Posts: 27
Another tidbit of info for everybody on this post. Running the all 0's test pattern for any longer than a few seconds on DS1 circuits is a complete waste of time. The all 0's pattern does not produce any pulses in the bitstream and is only used to verify that B8ZS encoding is being invoked on network elements, equipment & CPE

Page 2 of 3 1 2 3

Moderated by  Silversam 

Link Copied to Clipboard
Forum Statistics
Forums84
Topics93,740
Posts636,417
Members49,619
Most Online5,661
May 23rd, 2018
Popular Topics(Views)
Today's Birthdays
ebernhard, gman1205, Herb Parsons, jdews, nextlevel, ROGER IN FLA
Newest Members
blentz, RockyTop, Homer Domer, Lane, AMS Technology C
49,619 Registered Users
Top Posters(30 Days)
jsaad 7
Toner 6
Who's Online Now
2 members (dagwoodsystems, Curlycord), 102 guests, and 15 robots.
Key: Admin, Global Mod, Mod
Contact Us | Sponsored by Atcom: Business Phone Systems | Terms of Service

Sundance Communications is not affiliated with any of the above manufacturers.
©Copyright Sundance Communications 1998-2022
Powered by UBB.threads™ PHP Forum Software 7.7.5