Telstra cable/Paradise Wgtn

Running as slow as a dog here in Miramar this morning. Anyone else having
problems?

 

No problem in the Hutt valley.

 

Its still real slow and unresponsive for me too in Wellington

 

ping times to you seem to be fast and reliable

my com21 modem gets all claggy like that sometimes - cycling the power sorts
it out

 

I rang TelstraClear who admit I do have a problem with the modem and the
earliest they can get an engineer out to me is a week today! I explained it
wasn't just me who had this problem as someone else on the newsgroup was
experiencing the same thing and it turned out the help desk person didn't
know what a newsgroup was! I have a com21 modem too and have
unplugged/replugged it and still nothing - so how getting this posting out
then?
Dazed & confused, Miramar

 

My one is the same, you have to power recycle them when things are a bit
slow..,

 

Com21s have one advantage - on the back panel is a smaller plastic plug.
Behind this is a 4 pin connector. If you can find the information about
this - its the way to alter the connection speed. I don't know the
specifics - the Telstra guy would not give that info - but it would be an
interesting project for those with nothing better to do

 

From what I have heard from a few different sources, when each cable
modem boots up it contacts a T-FTP server (uses UDP rather than TCP
like a normal FTP server) @ Telstra. A configuration file is
downloaded to the modem that amoung other things contains the settings
for connection speed.

It gets this information from the cable network. On the Com21 modem it
is possible to get it to boot up without the coxial cable connected
and contact a TFTP server connected via the ethernet port (ie one you
have setup for the task).

One modems like the Motorola Surfboard the Ethernet Port is disabled
during boot up for this very reason.

When I asked a Telstra guy about this he said that even with the Com21
modem this still would not be possible as all modems have the ability
to attach a checksum to each packet at the Data Link Layer. The
checksum is generated from the contents of the downloaded TFTP file at
boot-up and at their end, their routers do a CRC check on every
packet.

If the CRC check is not OK then the packet is dropped.

I don't know how much of this is true but it certainly makes
interesting discussion on news groups.

==
Andy

 

Are there any kinds of diagnostic screens you can get to? Statistics
reports on bytes sent/received, numbers of errors, that sort of thing.

 

TFTP is used because it's lots simpler to implement than full FTP. It
also has no authentication. I've also seen it used to download program
code for booting devices.

What would not be possible--corruption of the packets causing bad data
to be loaded?

CRCs are not very strong. Even a 32-bit CRC only guarantees about a
1-in-65000 probability that a corrupted packet won't turn out to have a
valid-looking checksum.

 

Its a Medem not a Router..

 

Is that a yes or a no?