Connection between 2 sites
 

We have Virgin Media Business 350Mb at 2 sites and we have trouble when remoting from site 2 to site 1 via VNC whereby the connection often drops. I guess this means there is some kind of issue with either the upload at site 1 or the download at site 2. There are no noticeable issues in normal use otherwise. Ping and throughput are always good.

Both sites have the same service (350Mb dynamic) and setup (Hitron router in modem mode fed into a DrayTek router).

I guess the power levels and SNR is a good place to start. I'm alright with DSL stats but just can't work this out! I would be extremely grateful if someone would be able to glance over this and let me know whether anything looks obviously wrong. Thanks in advance!

Site 1

Downstream Overview
Force Downstream Frequency (MHz)
379
Apply
Port Frequency (Hz) Modulation Power (dBmV) SNR (dB) Channel
1 371000000 256QAM 0.000 40.366 28
2 219000000 256QAM 2.300 40.946 11
3 227000000 256QAM 2.300 40.366 12
4 235000000 256QAM 2.200 40.366 13
5 243000000 256QAM 1.900 40.366 14
6 251000000 256QAM 1.800 40.366 15
7 259000000 256QAM 1.600 40.946 16
8 267000000 256QAM 1.400 40.946 17
9 275000000 256QAM 1.400 40.946 18
10 283000000 256QAM 1.100 40.366 19
11 291000000 256QAM 1.300 40.946 20
12 299000000 256QAM 0.900 40.366 21
13 307000000 256QAM 1.000 40.366 22
14 315000000 256QAM 0.700 40.366 23
15 323000000 256QAM 0.500 40.366 24
16 347000000 256QAM 0.100 40.366 25
17 355000000 256QAM -0.100 40.366 26
18 363000000 256QAM 0.000 40.946 27
19 379000000 256QAM -0.200 40.366 29
20 387000000 256QAM 0.000 40.946 30
21 395000000 256QAM -0.200 40.366 31
22 403000000 256QAM -0.200 40.366 32
23 411000000 256QAM -0.300 40.366 33
24 419000000 256QAM -0.300 40.366 34
Upstream Overview
Port Frequency (Hz) BandWidth Modulation Power (dBmV) Channel
1 39400083 6400000 ATDMA 47.750 12
2 25800034 6400000 ATDMA 46.750 14
3 32600048 6400000 ATDMA 47.250 13
4 46200065 6400000 ATDMA 48.250 11

Site 2

Downstream Overview
Force Downstream Frequency (MHz)
379
Apply
Port Frequency (Hz) Modulation Power (dBmV) SNR (dB) Channel
1 371000000 256QAM 0.000 40.366 28
2 219000000 256QAM 2.300 40.946 11
3 227000000 256QAM 2.300 40.366 12
4 235000000 256QAM 2.200 40.366 13
5 243000000 256QAM 1.900 40.366 14
6 251000000 256QAM 1.800 40.366 15
7 259000000 256QAM 1.600 40.946 16
8 267000000 256QAM 1.400 40.946 17
9 275000000 256QAM 1.400 40.946 18
10 283000000 256QAM 1.100 40.366 19
11 291000000 256QAM 1.300 40.946 20
12 299000000 256QAM 0.900 40.366 21
13 307000000 256QAM 1.000 40.366 22
14 315000000 256QAM 0.700 40.366 23
15 323000000 256QAM 0.500 40.366 24
16 347000000 256QAM 0.100 40.366 25
17 355000000 256QAM -0.100 40.366 26
18 363000000 256QAM 0.000 40.946 27
19 379000000 256QAM -0.200 40.366 29
20 387000000 256QAM 0.000 40.946 30
21 395000000 256QAM -0.200 40.366 31
22 403000000 256QAM -0.200 40.366 32
23 411000000 256QAM -0.300 40.366 33
24 419000000 256QAM -0.300 40.366 34
Upstream Overview
Port Frequency (Hz) BandWidth Modulation Power (dBmV) Channel
1 39400083 6400000 ATDMA 47.750 12
2 25800034 6400000 ATDMA 46.750 14
3 32600048 6400000 ATDMA 47.250 13
4 46200065 6400000 ATDMA 48.250 11

Re: Connection between 2 sites
 

All of that is fine. The thing you need to do is ascertain whether it is the wan connection which is dropping or the prog which is establishing the connection. If you haven't got any network monitoring software in place I would setup one of these for each site so you can see if either site's connection is dropping. It will have a dual benefit in that not only will it let you know if you are getting random connection drop full stop, but it will also let you see if the connection drops specifically when when you are establishing that connection. You can get it going now from home if you know what the hitron ip addresses are for both sites.

Re: Connection between 2 sites
 

Thanks very much, I’ve setup the Think Broadband monitoring.

Just to clarify, the connection is not dropping, but the VNC connection is often terminated so something is causing that. In normal use (browsing etc) there is no issue.

Re: Connection between 2 sites
 

thought that would be the case. It is as if keep alives are being sent between the clients to maintain the connection and they are either being dropped or taking too long to arrive and you are losing the connection. Might be worth having a google and seeing if anyone else has had the same problem. There might be a setting somewhere you can change. Has this just started happening or is this the first time you have tried it?

Re: Connection between 2 sites
 

Difficult to say whether it’s new or been this way for a while as I don’t remote from site 2 to site 1 myself so it relies on others telling me there’s an issue, but I’m included to say it’s a fairly new problem.

The strange thing is that there is no issue remoting from site 1 to site 2 via VNC, only the other direction. I’m not sure what that suggests. It is via a VPN tunnel, not sure if that’s of any relevance.

Re: Connection between 2 sites
 

Thanks for the continued support. I think I may have found the cause of the issue. The MTU at site 1 was set to 1400 still from when we dabbled with the static IP service. Site 2 was correctly set to 1500. On changing this, everything seems alright so far...

Think Broadband monitoring is underway anyway and here's the last day. I think everything looks fine.

Site 1:

https://www.thinkbroadband.com/broad...19-06-2020.png

Site 2:

https://www.thinkbroadband.com/broad...19-06-2020.png

Re: Connection between 2 sites
 

I think you have clicked on the wrong link to share those graphs because they are private and invisible.

Re: Connection between 2 sites
 

Oops, let's try again.

Site 1:

https://www.cableforum.uk/images/local/2020/06/17.png

Site 2:

https://www.cableforum.uk/images/local/2020/06/18.png

Re: Connection between 2 sites
 

There's nothing wrong there

Re: Connection between 2 sites
 

Thanks for confirming. I think it was an MTU issue but will continue to monitor and keep you posted.

Re: Connection between 2 sites
 

Cool