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Connection quality

For many months we have had a very unstable connection with regular hub reboots and timeouts together with lots of dropped packets.

The first engineer came and changed the hub

The second engineer came and removed the 10db attenuator (which he said was very old, mjuch older than the installation?)

At this point he said it was completely fixed even though he saw it drop the connection just a few minutes later. (the power levels were better though).

The third engineer came (a "bench engineer") who did a speed test and said it was all fine.

It is not!

On average once or twice a day the hub is reporting

criticalNo Ranging Response received - T3 time-out;CM-MAC=----------;CMTS-MAC=---------;CM-QOS=1.1;CM-VER=3.0;

 

Since the bench engineer visited we have also seen dhcp errors

ErrorDHCP RENEW sent - No response for IPv4;CM-MAC=---------------;CMTS-MAC=------------------;CM-QOS=1.1;CM-VER=3.0;
ErrorDHCP REBIND WARNING - Field invalid in response;CM-MAC=----------;CMTS-MAC=------------;CM-QOS=1.1;CM-VER=3.0;

 

Of particular concern is the repeated and constant dropped packets. The telephone support and the engineers that have visited have all said things like "we dont guarantee ping times", "its your computer", "its works for me", "see i can still use the internet".

An example output of a ping test from the hub (not from the pc)


PING 213.105.9.24 (213.105.9.24): 64 data bytes
72 bytes from 213.105.9.24: seq=0 ttl=249 time=40.000 ms
72 bytes from 213.105.9.24: seq=1 ttl=249 time=10.000 ms
72 bytes from 213.105.9.24: seq=2 ttl=249 time=4420.000 ms
72 bytes from 213.105.9.24: seq=3 ttl=249 time=8960.000 ms
--- 213.105.9.24 ping statistics ---
10 packets transmitted, 4 packets received, 60% packet loss
round-trip min/avg/max = 10.000/3357.500/8960.000 ms

There is no way that this is correct behaviour.
For comparison this is the result from my low speed sky connection

Pinging 213.105.9.24 with 32 bytes of data:
Reply from 213.105.9.24: bytes=32 time=52ms TTL=247
Reply from 213.105.9.24: bytes=32 time=23ms TTL=247
Reply from 213.105.9.24: bytes=32 time=28ms TTL=247
Reply from 213.105.9.24: bytes=32 time=28ms TTL=247
Reply from 213.105.9.24: bytes=32 time=43ms TTL=247
Reply from 213.105.9.24: bytes=32 time=39ms TTL=247
Reply from 213.105.9.24: bytes=32 time=23ms TTL=247
Reply from 213.105.9.24: bytes=32 time=22ms TTL=247
Reply from 213.105.9.24: bytes=32 time=22ms TTL=247
Reply from 213.105.9.24: bytes=32 time=31ms TTL=247

Ping statistics for 213.105.9.24:
Packets: Sent = 10, Received = 10, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 22ms, Maximum = 52ms, Average = 31ms


I was previously asked to setup BQM by one of the telephone support although the engineers who visited said they had never heard of it.

15:14 15/06/200

My Broadband Ping - Sinai hub 3

15:14 14/06/200

My Broadband Ping - Sinai hub 3

There are  no wifi devices connected to the hub.There is currently virtually no internet usage at all on this connection for obvious reasons.

What can I do to get the engineers to understand that lost packets on a ping is proof that there is a problem somewhere 

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Message 2 of 17
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Re: Connection quality

Getting those errors a few times a day is pretty normal for a cable modem connection and can be ignored. Pings are also typically higher than an equivalent bt connection but should still be less than 50ms typically 20 to 30ms.

Your bqm also seems pretty decent and confirms the above is true for your connection. 

Can you post your up and down stats? These say much more about your connection. 

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Message 3 of 17
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Re: Connection quality

With respect I am not talking about pings being slightly worse.

We are talking about packet loss and pings being 1000000% worse

Up and down stats are irrelevant if the packets are lost

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Message 4 of 17
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Re: Connection quality

Up and down stats tell us if your cable to the cabinet is good or if there's a problem with your router or cabinet. If there's interference somewhere it could well mean lost packets and packets have a specific ttl and retry periods. 

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Message 5 of 17
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Re: Connection quality

OK here you are but they are pretty meaningless as there is no one using it

 

Upstream bonded channelsChannel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1394000074.15512064 qam2
2258000004.15512064 qam4
3326000004.15512064 qam3
4462000144.15512064 qam1


Upstream bonded channelsChannel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA0000

 

 
Downstream bonded channelsChannel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
11627500007.840256 qam4
21387500008.540256 qam1
31467500008.340256 qam2
4154750000840256 qam3
51707500007.640256 qam5
61787500007.540256 qam6
71867500007.540256 qam7
81947500007.140256 qam8
92027500006.640256 qam9
102107500006.540256 qam10
112187500006.640256 qam11
122267500006.540256 qam12
132347500006.840256 qam13
142427500007.140256 qam14
152507500007.340256 qam15
162587500007.140256 qam16
172667500007.440256 qam17
182747500007.440256 qam18
192827500007.540256 qam19
202907500007.540256 qam20
212987500007.840256 qam21
223067500007.840256 qam22
233147500007.940256 qam23
243227500007.940256 qam24


Downstream bonded channelsChannel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1Locked40.3210
2Locked40.9290
3Locked40.3210
4Locked40.3190
5Locked40.3210
6Locked40.3170
7Locked40.370
8Locked40.3110
9Locked40.3120
10Locked40.3210
11Locked40.9120
12Locked40.390
13Locked40.9100
14Locked40.340
15Locked40.980
16Locked40.390
17Locked40.360
18Locked40.380
19Locked40.3110
20Locked40.3120
21Locked40.3120
22Locked40.390
23Locked40.3220
24Locked40.9230
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Message 6 of 17
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Re: Connection quality

Your bqm also seems pretty decent and confirms the above is true for your connection. 

Errm, no it isn't in the slightest bit decent.  Both charts show evidence of complete interruptions to connection, and multiple events of latency shooting well over 100ms.  That connection is neither reliable, nor suitable for gaming and streaming.

Question for brianteeman: Where's the local VM cabinet that you connect in to ?  Is it in a location where it is particularly exposed to midday sun, and generally with the long axis running roughly east-west?  

I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more

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Message 7 of 17
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Re: Connection quality

Sorry andruser I have no idea

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Message 8 of 17
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Re: Connection quality

@andruser I just realised the significance of your question and I can see your thinking. Unfortunately thats not going to be the case as although the two bqm I shared would suggest that other bqm show it happens just as often in the early hours

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Message 9 of 17
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Re: Connection quality

Andruser. It only has a few interruptions of service which is what I've come to expect from virgin and the pings are far better than my connection.

I would however suggest from your stats that it appears to be a problem with the cab. Good luck getting it fixed though. These things can take months from what I've seen in the past.

This is my bqm for comparison 

https://ibb.co/DM4ycWj

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Message 10 of 17
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Re: Connection quality

Just because you have a bad connection that may or may not be worse than mine does not negate my issue or that its a fault

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