tyco
join:2007-11-17
| Download Packet Loss - stumped everyone
I currently have Speakeasy 3.0/768 and have had them for 7 years without any issues at all.
In the last week, I noticed my connectivity started to have issues - web page freezes, disconnects vpn, etc. I did the speed tests and noticed my download speed had plummeted. I previously had a stead ~ 2.8Mbit download and ~ 600 upload.
Now, the download is usually 100 - not mbit, kbits.. It seems to freeze at verious points - sometimes it freezes forever. The upload is a constant stream getting the speeds I wanted.
So...we did all the normal troubleshooting:
- power cycled modem
- Removed linksys router
- changed ethernet cables
- used multiple cpus
Called speakeasy, they checked a few things:
- margins - look good at 25 down/11 upstream
- reprovisioned the dsl
- couldn't find anything wrong...
- recommended a new modem - so sent me one next day
Received new modem - same issue:
- tried multiple computers
- different dsl lines
- am at the specific network access point at my home - no other phones attached
- speeds still the same- packet loss downloads / uploads fine..
Called speakeasy again:
- reprovisioned circuit
- tried different speeds
- called covad - reset the DSLAM Card
- Ran an MLT test - everything looks good. I am under 6000 feet.
- DSLAM is not anywhere near capacity - maxed at 80%. We did tests when it was at 20%.
Basically everyone is stumped - they are sending out a covad tech - but it will be 5 days.
In general speakeasy has been extremely helpful - spent hours on the phone with me trying everything they can from their end.
Does anyone have any other ideas on what impacts download speed only? Any other tests I could run?
Thanks in advance to all. |
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tkdslr
join:2004-04-24
Pompano Beach, FL | Did the latency (ping) to the DNS servers change??? |
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tyco
join:2007-11-17
| reply to tyco
Pings to the DNS servers don't really show any latency changes - I simply get a request timed out every so many pings.
What is interesting is that at the normal ping size it only has issues every 25+ pings or more. As I increase the size it happens more frequently. Until I am just over 2k where it will timeout within 5-8 pings.
Sometimes you see a large response time increase right before I get a request timed out - but usually it times out.
The issue definitely shows itself with larger sized packets/downloads. |
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tkdslr
join:2004-04-24
Pompano Beach, FL
 ·Speakeasy
edit:
November 24th, @09:26PM
| said by tyco  :Pings to the DNS servers don't really show any latency changes - I simply get a request timed out every so many pings. What is interesting is that at the normal ping size it only has issues every 25+ pings or more. As I increase the size it happens more frequently. Until I am just over 2k where it will timeout within 5-8 pings. Sometimes you see a large response time increase right before I get a request timed out - but usually it times out. The issue definitely shows itself with larger sized packets/downloads. That is a characteristic symptom of a routing loop..
»en.wikipedia.org/wiki/Routing_loops
A misconfigured router is sending packets down the wrong pipe. When it gets to the other end it gets forwarded back the other direction or it may contain additional routers in the loop.
This continues until the TTL countdown expires*(128 routing hops).. Each misdirected UDP packet causes intense bursts of full speed traffic along with a mess load of ICMP redirect packeta, and DNS lookups.
Fresh (misdirected) packets are usually injected by one or more UDP based services and over time, multiple instances of these sservices have a tendency to sync up with one another.
I.E.. If you're an admin, You'll see huge bursts of traffic peak losses at 1 minute intervals.. then 30 second intervals as the problem worsens, etc.. (I.E. the default timeout intervals for these services.) |
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tyco
join:2007-11-17 |
Thanks Tkdslr - do you know what I can do to see if a routing loop is happening? Or what I can ask speakeasy - or will they know what to check?
Thanks in advance.. |
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tyco
join:2007-11-17
| Well I was still having the issue last night until I went to bed around 11:30PM.
I didn't try it this morning - but I came home from work today and boom - my connectivity is back. I am doing solid 3.3+ downloads again.
I have not changed a thing at my house - at this issue was going on all last week and weekend.
Any idea what could have caused it? I actually wish it was still happening since Covad is coming out this week to install a circuit - I wish they could have identified the issue so if it happens again I know what to tell them. |
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