Trouble with B2B fiber connection
DComTalk.com Forum Index DComTalk.com
Discussion of VoIP, VPN, Video Conferencen, DSL and other data commucations.
 
 FAQFAQ   MemberlistMemberlist     RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 
Google
 
Web dcomtalk.com
Trouble with B2B fiber connection

 
Post new topic   Reply to topic    DComTalk.com Forum Index -> Cabling
Author Message
Nickneem
Guest





Posted: Wed Aug 03, 2005 4:20 pm    Post subject: Trouble with B2B fiber connection Reply with quote

I have a fiber link between 2 buildings (distance approx. 500 meters)
3com superstack II 3000 on one side and HP2424M on the other.
Problem is I can't get 100 mb half or full duplex to work properly.
Roadkil's Comtest (http://www.roadkil.net/) shows an 9000 kb/s out but
the bytes in's stay below 50?
I tried to set both sides manually of course, but I get the best
results by setting it to 10mb half duplex 468/1144.

If I run the same test in one building (so without using the fiber) I
get 8000/8000, 10000/5000, 9000/9000, etc.


Thing is that I need to copy a 6 GIG Oracle dump file nightly between
the two buildings and I need the speed 8-)


Anyone can shine a light on my prob?


Thanks in advance,


Mike
Back to top
Perkowski
Guest





Posted: Thu Aug 04, 2005 4:20 pm    Post subject: Re: Trouble with B2B fiber connection Reply with quote

Nickneem wrote:
Quote:
I have a fiber link between 2 buildings (distance approx. 500 meters)
3com superstack II 3000 on one side and HP2424M on the other.
Problem is I can't get 100 mb half or full duplex to work properly.
Roadkil's Comtest (http://www.roadkil.net/) shows an 9000 kb/s out but
the bytes in's stay below 50?
I tried to set both sides manually of course, but I get the best
results by setting it to 10mb half duplex 468/1144.

If I run the same test in one building (so without using the fiber) I
get 8000/8000, 10000/5000, 9000/9000, etc.


Thing is that I need to copy a 6 GIG Oracle dump file nightly between
the two buildings and I need the speed 8-)


Anyone can shine a light on my prob?


Thanks in advance,


Mike

Id call up the contractor who put the link in and describe what is

happening. Could be a bad connector on end. Maybe a bad patch cord?
replace the patch cords before calling the contractor. Maybe the
connector isnt fully inserted into the switch on your receive end. Or
it could be the any of the splice points between the buildings.

Check both connector ends in each building. I cant how many times I had
customers complain about a fiber link not working where I went out there
and it ended up being THEIR bad patch cords. I billed them for the call
and sold them their patch cords.

Good Luck

Joe Perkowski
Back to top
Dale Farmer
Guest





Posted: Fri Aug 05, 2005 8:20 am    Post subject: Re: Trouble with B2B fiber connection Reply with quote

Nickneem wrote:

Quote:
I have a fiber link between 2 buildings (distance approx. 500 meters)
3com superstack II 3000 on one side and HP2424M on the other.
Problem is I can't get 100 mb half or full duplex to work properly.
Roadkil's Comtest (http://www.roadkil.net/) shows an 9000 kb/s out but
the bytes in's stay below 50?
I tried to set both sides manually of course, but I get the best
results by setting it to 10mb half duplex 468/1144.

If I run the same test in one building (so without using the fiber) I
get 8000/8000, 10000/5000, 9000/9000, etc.

Thing is that I need to copy a 6 GIG Oracle dump file nightly between
the two buildings and I need the speed 8-)

Anyone can shine a light on my prob?

Thanks in advance,

Mike

Get some alcohol swabs and a can of compressed air and clean
all the fiber connectors. Sometimes all it is is dirt. Then switch the
fibers at each end to see if the trouble stays with the fiber or with
the port. Switch patch cords to see if you have a bad patch cord.
Also be sure the patch cords are the matching diameter as the
interbuilding link fiber. Then it's time to bring in an OTDR and
someone who knows how to use it to troubleshoot.

--Dale
Back to top
Nickneem
Guest





Posted: Fri Aug 05, 2005 4:20 pm    Post subject: Re: Trouble with B2B fiber connection Reply with quote

Thank you all for your suggestions, I've found the solution thanks to a
Arie Goldberg:
http://groups.google.com/group/comp.dcom.lans.ethernet/browse_thread/thread/e0738cdd697ed1f7/6359ab000b23a3c7?lnk=st&q=Arie+Goldberg+full-duplex+modes&rnum=1#6359ab000b23a3c7

I hyperterminaled into the 3com 3000 and the HP2424 and changed the
settings for the fiber port.
They were all on default and that means 100mb Half Duplex.
The stats showed millions of CRC align errors and late events not to
mention the collisions...
I used to have ping -l 65500's with timeouts and 140 ms response time
and now they'
re as steady as a heartbeat and no timeouts!

Imagine the problems we had and the costs we've made tuning the
backoffice of every application we run (ERP, WMS).
All due to a misconfiguration of the hardware... sniff...

Thanks again and I hope this posting will help another poor soul!

Regards,

Michael
Back to top
 
Post new topic   Reply to topic    DComTalk.com Forum Index -> Cabling All times are GMT
Page 1 of 1

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




VoIP Solutions: Telephone Systems Electronics Satellite TV Tech & Gadgets
Powered by phpBB