5% packet loss - what to do?

surround

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Hi guys,

I'm having a bit of a problem with my 4mbit ADSL line. On average I get about 5% packet loss as confirmed by pingtest (http://www.pingtest.net/result/13950398.png) and by manual pinging.

I've logged multiple tickets with Telkom to investigate it but I never get anywhere with them. So, I've done some investigation of my own and this is what I've come up with:

1. The problem is not in the wiring of my house. (I crawled around in the roof and managed to place the router on the line that comes in from the pole outside. This did not solve the problem)
2. The problem is independent of any service providers. I've tried Telkom, WA and Afrihost
3. The problem is independent of the router. I've tried various.
4. The problem seems to be located between my router and my router's gateway. Confirmed this by pinging and reverse pinging to various hops in my traceroute.
5. A friend of mine who lives in my neighborhood seems to be having the same problem.
6. Correct me if I'm wrong but I think my line attenuation is ok: (down 52db, up 25.5db)
7. My line's noise margin is 9.3db down and 12.0db up. This is ok too right?
8. The problem does not go away if my line speed gets dropped to 384kb/s
9. My downstream traffic seems to be unaffected (I get 400+ KB/s easily) but my upstream traffic is slow as hell (2KB/s). This is killer on sending attachments with email.
10. Time of day does not matter. There is packet loss 24/7
11. I think my ICMP packets get lost on the upstream, not downstream but that's just an assumption.

From my investigation I'm pretty sure there's something wrong at my exchange but I'm just not knowledgeable enough to be able to tell the Telkom reps what to look for. I've tried explaining everything to them but I'm met with telephonic blank stares. (I've been told to try change my DNS server though, because, you know, that's gotta be the problem :erm:)

Anyone know what magic phrases I can tell the Telkom reps so that they'll know what the issue is?
 
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Think its your line, my router shows the following:-

ADSL Link Downstream Upstream
Connection Speed 4096 kbps 512 kbps
Line Attenuation 16 db 4 db
Noise Margin 18 db 12 db

so your downstream attenuation is a bit high...
 
Hey,

AFAIK a 52db line attenuation is too high for a stable 4Mbps ADSL connection! You should either let Telkom synchronize your line to 2Mbps OR downgrade your line to 512kbps if you want to increase your stability.
Perhaps just ask Telkom to find out how far you are from the exchange, so that you can get a rough estimation of what the line attenuation should be on a near perfect cable. A distance further than 3.5km from the exchange would result in you having a Line Attenuation of > 50dB.

Here's a thread that explains Line attenuation & SNR margins: http://mybroadband.co.za/vb/showthread.php?186156-Understanding-SNR-and-Attenuation-Rates\

Edit: Btw, how did you test your line at 384kbps? Did you ask Telkom to let it synchronize at 384kbps?
 
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so your downstream attenuation is a bit high...

I assumed so at first too but the problem persisted when we dropped the line speed to 384. Oh, and my downloads seem fine. My uploads are borked.
 
Edit: Btw, how did you test your line at 384kbps? Did you ask Telkom to let it synchronize at 384kbps?

Yes, the Telkom rep progressively decreased my line speed and it didn't clear up the dropped packets.
 
I am having the same issue:

DSP Firmware Version DMT FwVer: 3.10.17.0_A_TC, HwVer:T14F7_5.0
DMT Status Up
Operational Mode ADSL G.DMT
Upstream 512 kbps
Downstream 4096 kbps
SNR Margin (Upstream) 20.0 db
SNR Margin (Downstream) 25.0 db
Line Attenuation (Upstream) 3.5 db
Line Attenuation (Downstream) 8.0 db
 
I had a similar thing on my line that I couldn't seem to resolve - kept dropping packets and line synced at 384, then kept dropping - I thought my wiring/connectors were fine, until I started checking each connector carefully The main RJ11 jack plug (that comes from the outside pole wire) was all black on the copper connectors form a lightning strike a month or so ago - swopped the jack adapter and the wallbox for a new one and my line was back up to normal.
 
Thanks howardb, I'll recheck all the connectors. I have had a lightning strike take out my previous modem a month or two back. Maybe you're onto something here.
 
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