[c-nsp] Strange DS3 Problems

[Andy Dills]

On Mon, 7 Jan 2008, Adam Piasecki wrote:

> 1) The max download speed i've ever gotten is 700kb/s, this doesn't seem
> right at all for 10/10mb dedicated, 45mb burstable.

Is there anything you can download directly on the other end of the DS3, 
to confirm it's an issue with your DS3 and not with upstream capacity? 
Also, sorry to be pedantic, but you're sure it's 700kbps and not 700kBps? 

> 2) the Ds3 is bouncing. It goes into a down/down state and i'll have a FERF
> alarm light on the router. This will clear in about 20-30secs without me
> doing anything.
> It seems to happen more when the Ds3 is under load, though it has happend
> without any load.

What does the provider see on their interface stats?

> What I can do,
> 
> 1) I can ping the living daylight out of the ISP serial side IP, 20000 pings
> 3700byte packets with 0% lost, 3ms max.
> In past this to me, would mean a clean working ds3.

Just to be safe, try doing a range sweep with 0xAAAA (alternating 1s and 
0s). DS3s are a lot more sensitive to alternating bits, and will help 
expose seemingly solid circuits. Might turn out that you need to increase 
attentuation, wouldn't be the first time.

> 1) What is the rx FEBE since last clear counter mean? I notice this is the
> only sort of error i'm getting now.

It's an indicator that the far end received a c-bit parity error. It's  
possible you need to attenutate the tx from your router to the fiber 
converter, in addition to the rx.

> 2) Is a 7206 non-VXR NPE 200 strong enough for a full DS3, if i'm just doing
> a default route, and a very small ACL.

Definitely.

> 3) Is it possible that i have a BAD PA-T3, I did have it connected without
> the Attunator for sometime,

Have you done loopback testing with a short hard loop cable? It generally 
eliminates the hardware. See: 

http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a008034418d.shtml

> 4) Has anyone used Fiber to DS3 converters in the past? Good/Bad?

I have not, so in my mind that's the most suspicious issue, especially in 
the absence of detected errors on the ISP side.

>  cablelength 10

Try making that > 50, see what happens. Probably nothing, but just in 
case.

Andy

---
Andy Dills
Xecunet, Inc.
www.xecu.net
301-682-9972
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