UPC DOCSIS implementation

the_law

I'm in Rathmines and on the 20/1.5 service from UPC. My modem will only ever sync on two channels regardless of how busy they are.

They are 'channel 30' at 426250100 Hz and 'channel 31' at 482000000 Hz.

I'm interested to know what other users around Dublin (and otherwise) find in their local area... Basically with only two channels the maximum usable throughput on my whole street (well over 100 households) is 76 Mbit (38 per channel). This certainly explains why contention becomes an issue at peak times.

UPC aren't running DOCSIS 3, which allows for sharing of channels, so once you sync on a particular channel, you're not going to move very frequently. If 2 20Meg users start downloading on the same (38Mbit) channel, it's full...

Sometimes, when I experience bad contention, rebooting the modem causes it to select the other channel (where there is less contention) and my speeds increase.

If you're on the Scientific Atlanta modem, here's how to check:

http://192.168.100.1/_aslvl.asp and login with user: admin pass: W2402
Set ethernet to Access Level 3 and enter W2402 in the password field (leave user empty), submit and go back to main page. The Signal tab is then unlocked, and will tell you what your downstream and upstream frequencies are.

I'm no telecoms expert, so maybe there is someone on here who can explain if I've missed something that would mean these figures show less horrendous contention. I don't know why UPC don't allocate more downstream frequencies to data - surely they have some left over after digital TV?

_CyRuSS_

i don't know how you got that password but thank you! it really annoyed me that this info was locked out of my modem, and i have had problems with my modem recently so wanted to see the log!

as for channels, well my downstream is channel 40 426250000 Hz.... upstream channel 2 22800000 Hz, in Dublin 4

the_law

I think I found that password on boards somewhere...

If you're having contention issues, try turning off and on the router to see if it syncs on a different channel. It's interesting to see you're on a different channel... would be really interesting to see how many channels are active in your area.

I forgot to say that after some time the access rights will be downgraded by UPC again... you can just repeat the process. I don't know why they don't make it accessible, as you can't actually change anything that affects the operation of the router.

_CyRuSS_

i remember in my old place with one of NTL's old old old cable modems from years ago there was some application i could run which could sniff out the lines and see all the channels, but really can't remember how it was done again think i got the info from somewhere on this page http://homepage.ntlworld.com/robin.d.h.walker/cmtips/index.html but thats probably old and redundant now, and i dont know where it is on that site...

yeh i dont know why they hide this information, in my old house i had the purple ntl 250 modem... and none of the stuff on that was locked out, so doesn't make sense to lock it out on their newer modems

*edit* i think the application was DocsDiag could see some things about ntls network.. http://homepage.ntlworld.com/robin.d.h.walker/docsdiag/ now i dont know if that still works, i used it several years ago, they upgraded docsis since i think... also prolly against TOS i dont know

vibe666

that password is floating round the net and has been mentioned here quite a few times too.

i'm pretty sure i've posted it before after googling "scientific atlanta admin password" or something like that and finding it on some blog somewhere.

BOZG

No idea what any of it means but here's mine on 20/1.5:

Channel 51 - 482000000 Hz downstream
Channel 2 - 58400000 Hz upstream


Dublin 9

coldfire1x

Downstream
Channel ID: 1
Downstream Frequency: 426250000 Hz

Upstream:
Channel ID: 3
Upstream Frequency: 19600000 Hz

Dublin - 8

LEIN

DS
498000000 Hz
CH1

US
61600000 Hz
CH4

Greystones

Checked a few times now and its constantly changing.

trdublin

Downstream
Channel ID: 9
Downstream Frequency: 490000000 Hz

Upstream:
Channel ID: 3
Upstream Frequency: 29600000 Hz

Dublin - 4

I wondered if these channels have anything to do with DHCP problems I sometimes have?

Thor

my stats 20/1.5mb

Downstream
Channel ID: 40
Downstream Frequency: 426250000 Hz

Upstream:
Channel ID: 4
Upstream Frequency: 22800000 Hz

in dublin 14(dundrum)

ksl19

Downstream:
Ch 1 426250000 Hz

Upstream:
Ch 3 58400000 Hz

Dublin 9
Drumcondra

BOZG

BOZG wrote: »

No idea what any of it means but here's mine on 20/1.5:

Channel 51 - 482000000 Hz downstream
Channel 2 - 58400000 Hz upstream


Dublin 9

Checked again. Same Channels.