Internet Randomly Disconnects then Re-connects

[Martyn]

Only happening recently just the whole internet cuts off, then reconnects, i don't see no difference in router settings or any error or anything.

[Knelf]

Hiya

Sounds like my problems (see "Quality of Support" thread in this forum) I've had same issues for months and months now. Support has been crap both times but this time we have a guy coming to replace the modem (old 5 yrs in place teryon terajet 210) on thursday.

If that doesn't fix it we're gonna walk. I'll keep that thread updated on how things go.

[fatassmichael]

Knelf, if you are on QAM256 modulation, then the terayon modems have known problems, so a new modem *should* sort the disconnections, providing your power levels are also ok.

[Knelf]

Hey thanks! Sounds positive so hears hoping they actually show up (reading quite of people who take time off work and they don't!).

Any way I could actually check if I'm on this QAM256 modulation?

[fatassmichael]

IIRC the terayon doesn't have a web interface, eg, http://192.168.100.1 , but you can always try that.
Edit: If you post the area your in, maybe others could let you know.

[Knelf]

Yeh been looking into this milarki. Terayon doesn't have an internal address. Been looking at using DOCSIS to find it but its looking likely that VM have disabled SNMP traffic as no responses were found by the prog and I didn't see a single response on watching tcpdump on the external interface of our server either. Running docsis against our hub (supports snmp) worked so the prog is definitely working ok but externally it looks like "no one is home" which didn't supprise me.

I'm in NG7. An ex NTL area.

Incidentally can someone explain this:

When I do a tracert I get the first hop from the server as 10.249.28.1 which is suposedly the UBM. DOCSIS then runs a scan all round that ip address using my CM's ethernet address to match against to find my "cable modem's IP address". My question is... if my CM has an IP address then how come it doesn't show up in a traceroute? I'm not entirely clear on what the cable modem "is" when its connected to my server as its the server that gets the VM DHCP assigned address. If this is the case then what does the CM get? If I'm understanding DOCSIS right then there is a magical hidden IP address that the CM has which I don't know about, is this right?

or am I just getting confused? ;) Thanks for any info. All good learning

Knelf

---------- Post added at 12:24 ---------- Previous post was at 12:07 ----------

ah Right sorry I was being a muppet. Of course the server has a Default Gateway pointing at the UBM (supposedly) so of course it isn't going to route via the CM (duh!)

Apparently a CM more or less acts as a bridge between the LAN and the HFC. Ho hum, at least I'm learning.

[TheNorm]

Only happening recently just the whole internet cuts off....

I had a similar problem with my wireless access point, and after much detective work discovered it was due to the power supply overheating, cutting out, then coming back on (etc.)

Moved the power supply to a "draftier" place and the problem was solved.

[punky]

This has been happening to me a lot lately. I'm on 4meg with a STB in London.

[Lew]

Been happening here the last day or so. 20Mb in Fleet, Hants.

[Trybrow]

thats about the size of it for me too. just poor. when they sold it to me they said 4mb broadband. the only problems caused by congestion should be a few kilobytes here and there. i shouldnt be getting 10kbps uploads and near 20 kbps downloads. but they straighten out after a while. i have a choice. i could cancel my contract and tell they to whistle. they probably wouldnt prosecute someone on benefits. plus id actually have a case, they wouldnt want there terms and conditions being scrutinised in court and potentially changed so i believe theyd just let me off. they other choice is put up with it untill the end and since im not working at the moment i might as well do that.

[Knelf]

Just a quick reply to my own stuff in case anyone is interested. Managed to find out my cable modem IP address using tcpdump on the house server's external card (the one thats connected to the modem) while powering the modem on. You look for an arp request packet from the modem that has the same ethernet address as your modem (printed on the modem normally). No luck with getting DOCSIS stuff to work with that address though. The request goes via the default gateway and it looks like VM are blocking smtp traffic so no responce. Ah well. someones told me on here that the area I'm in (NG7) has some kinda radio modulation that causes problems for my modem so I'm hoping a change will fix things.