Router or modem?

[pawz]

Hello, hoping you network whizzes will be able to help us with a puzzling (to us) problem.

We are on cable broadband. A few months back we asked for a new digital set top box because the tv was occasionally freezing, and took the opportunity to have a stand-alone cable modem as well rather than the integrated one. Up until then we had enjoyed a reliable broadband connection overall.

We started losing connections after the switch to a stand-alone modem - which were easily enough sorted by simply turning the modem off and then on again, but as time has gone on, the dropouts got more frequent. Eventually we phoned Virgin and got connected to a lady in India, who had us switching things off, trying different computers and so on, and who concluded that there was nothing wrong with the modem, and so it must be our computers (all of them!) or our router. We retired our Linksys and bought a D-Link. The drop-outs continued. We would be on the web one moment, and then not. The computers could see the router and vice-versa, there seemed to be nothing wrong 'our end', but the modem would be flashing its sync and ready lights ( which indicates a problem), and turning it off and on was not solving the problem.
When this got to be happening two or three times every day, we phoned up again and said we wanted another modem. The guy on the other end said he could access our modem behaviour for the last five days, and that it had behaved perfectly in that time, so it must be our router. He said that we needed to disconnect from the router and run just one ethernet connection to the modem for 24 hours. We did that - and the modem behaved perfectly - not one dropout.
We have been through four routers with this problem - 2 wireless Linksys, an ethernet only Linksys, and now the D-Link. They can't all be faulty. Have you any suggestions as to where we look for a solution? We are both fairly savvy with computers as we mend them for other folk all the time, so feel we have capabilities for fixing this problem if only we knew where to start. Just a clue.... please :)

[Bill_Bright]

So what's left? The wiring. I would replace the Ethernet cable between the cable modem and router. You may also need to make the coax cable run as short, and split-free as possible.

[pawz]

the cable from the modem comes up the wall and through to an RJ45 wall jack in the room above, and with the router disconnected, has been directly linked via ethernet to my machine - and everything was fine.

Odd thing is, we have now reconnected the router, using the same ethernet cable as before, and everything is STILL fine.

I wonder if simply disconnecting it and then re-connecting it might have 'done something' - but time will tell. We have had a couple of trouble-free days in a row before. If it continues to behave over the next seven to ten days I shall dare to believe the problem has actually gone away... ::)

[Bill_Bright]

-{ Quote: "the cable from the modem comes up the wall and through to an RJ45 wall jack in the room above, and with the router disconnected, has been directly linked via ethernet to my machine - and everything was fine. " }-So is the router in the same room as the modem? My concern would be the RJ-45 wall outlet, and Ethernet cable between the modem and router. These are cheap cables, and cheap crimp-on connectors.

-{ Quote: "Odd thing is, we have now reconnected the router, using the same ethernet cable as before, and everything is STILL fine.

I wonder if simply disconnecting it and then re-connecting it might have 'done something' - but time will tell. " }-Perhaps disconnecting and reconnecting the cable scrapped clean the contacts. Or, as I often suspect, your ISP denied any problems on their end, but refreshed your settings anyway, clearing the problem.

Or there could be an issue with the drop into your house. Moisture in the cable or loose connection in a distribution box somewhere.

[pawz]

No, the modem is downstairs, computers upstairs. Bill, we are inclined to think the ISP tweaked something their end, because it has been behaving perfectly ever since we spoke to the guy who advocated the 24-hour solo connection.

The jack upstairs was installed by my hubs, who is a mature electrical engineer (and a carefully fussy one at that), and we had not found any problems with anything in the several years it has been there, until the stand-alone modem was brought into play.

Thank you for your interest and efforts to help. Greatly appreciated:thumb:

[Bill_Bright]

-{ Quote: "Bill, we are inclined to think the ISP tweaked something their end" }-I would not be surprised. They often "re-authenticate" just as a matter of routine, which causes the modem to complete a handshake with their system again. That alone is often enough to set all right, but without pinpointing the exact original problem. It allows ISPs to point fingers anywhere, but inward.