roblev
August 23rd, 2001, 08:43
I was crusing around the net and I found the following article on a hacker site, maybe it is of some interest:
Introduction
------------
This is mainly for Terayon modems under Shaw. Sure it may be helpful with
motorola modems, but mainly Terayon.
Thanks, Shaw, for throwing out the kewl-e-o RF Technical Field Guide, and
putting an unlocked chain over the dumpster for a couple of hours won't keep
phreaks out! Oh, there was another faction that promoted ignorance too, nazis.
As far as I can tell, not much different from Shaw and Telus...
@HOME RF Concepts
------------------
Here is an example of a partial open problem in which the forward levels
are all within acceptable limits: Ch 2 / 2dB, Ch 6 / 5dB, Ch 14 / 19dB,
Ch 27 / 10dB, Ch 70 / 12dB. Opens are caused by crappy Shaw stuph. We'll
use this as an example for this section.
The main problem the open will cause to a cable modem can be seen in the
signal roll-off in the return path. The higher the frequency or channel, the
better signal can jump across a partial open connection. When the frequency
gets lower, the roll-off is more pronounced.
The example, shown above, has 2 elements acting upon it: RF power level and
the severity of the partial open. If the RF power level were 10dB lower, we
would normally see problems with Channels 2-6 while the higher channels would
appear okay. However, if the partial open were more severe, the roll-off would
also occur at higher channels.
It is important to know that a cable is only an RF convertor for computers.
The signal from the headend [forward path] arrives at frequency just below
Channel 14 while the singal from the headend from the computer [return path]
is below Channel 2 at 24MHz.
Modem Light Sequences
---------------------
Understanding the modem light sequences will help you understand what the hell
your modem is up to. First, here is a key of what my abbreviations will look
like: [You know, the 4 l'il lights on the front right of the modem]
+----+-----------------+ Oh, new and old modems lights will be different.
| NL | No Light | New modems lights will go from left-to-right:
| SG | Solid Green | Send, Receive, Message, Online; while old modems
| BG | Blinking Green | go: Send, Receive, Online, Power.
| SR | Solid Red |
| BR | Blinking Red |
+----+-----------------+
Two more things to remember:
1. If the Online is not solid green than you can't go on the internet.
2. Red lights are evil. [Duh!]
Below are typical light sequences and what they mean.
Online:
+----+----+----+----+ Normally this means you're online, but if your modem is
| NL | NL | NL | SG | really messed, and getting this, then you may be getting
+----+----+----+----+ packet loss or bad connections due to RF issues.
No Return:
+----+----+----+----+ This means the modem has failed to find a return path
| BG | BG | NL | SR | to the headend. Shaw's faulty equipment or low RF
+----+----+----+----+ level's are probaly causing this.
No Signal:
+----+----+----+----+ This means their is no signal getting to the modem
| BG | BG | NL | NL | either due to more crappy Shaw ---- or more RF issues.
+----+----+----+----+
Boot Failure:
+----+----+----+----+ This one is simple, your modem cannot POST [Power On
| NL | NL | SR | SR | Self Test]. Try another power supply, if that don't work
+----+----+----+----+ you're gonna go to Shaw and get yourself a new modem.
No Traffic Contract:
+----+----+----+----+ When a modem attempts to conect to the network but fails
| BG | BG | NL | BG | it will blink 3 green like the top chart. After 15-30
+----+----+----+----+ minutes of failing, the modem will give up and blink 4
| BR | BR | BR | BR | red. This problem might happen if you transfer your
+----+----+----+----+ account or if your modem gets ----ed.
Boot Sequence: [What the lights will be like while booting]
+----+----+----+----+-------------------------------------+
| NL | NL | NL | SG | Power On Self Test |
+----+----+----+----+-------------------------------------+
| BG | BG | NL | NL | Scanning for Forward Signal |
+----+----+----+----+-------------------------------------+
| SG | BG | NL | NL | Scanning for Return Signal |
+----+----+----+----+-------------------------------------+
| SG | SG | NL | NL | Locked onto Signal |
+----+----+----+----+-------------------------------------+
| SG | SG | BG | NL | Registering on Teralink |
+----+----+----+----+-------------------------------------+
| BG | BG | NL | BG | Not Authorized for Connection |
+----+----+----+----+-------------------------------------+
| NL | NL | NL | SG | Modem Online |
+----+----+----+----+-------------------------------------+
| BG | BG | NL | SG | Computer Connecting to Internet |
+----+----+----+----+-------------------------------------+
Modem Levels
------------
There is a webpage, called "Krusty", that cable modems report their RF signal
levels to. The page is located at members.home.net/shawtech, however, it
requires a password and username to login, and I'm not going to give that out.
Lets just pretend you made a few smart calls, or trashed at the right time and
got a login username and password.
You login and navigate your way to the Terapro Level Test page. [Yup, there is
one for Motorola modems too!] Once there, choose the Teralink [Router] your
modem is located on and enter your serial number. [You may have to do trial
and error or social enigineering to get those.] Initiate the modem test and
this is what will be displayed:
+------+---+-------+--------+--------+-----+----------+----------+---------+
|Serial|VCI|Receive|Transmit|Software| PC | Time |Downstream|Upstream |
|Number| | Level | Level |Revision|Light|Registered| S/N ratio|S/N ratio|
+------+---+-------+--------+--------+-----+----------+----------+---------+
| * | | | | | | ** | | |
| |32 | 3.0 | 50.0 | 1.84 | On | | 29.0 | 20 |
| | | | | | | | | |
+------+---+-------+--------+--------+-----+----------+----------+---------+
* your serial number, I didn't have enough space to display it though.
** It'll say it by the days, hours, minutes, and seconds, I just didn't have
enough space to display that either.
Okay, so it won't really look that crappy, but you get the idea. The important
info is Serial Number, Receive Level, Transmit Level, Time Registered as well
as Down and Up Stream Signal to Noise Ratio. VCI, Software Revision and PC
Light aren't important.
Receive [RX] and Transmit [TX] levels are important, as I said before. The RX
are roughly the same as the levels on Channel 14 and mirror the levels the
modem receives. Therefore, an RX of 10 = 10dB @ Channel 14. Acceptable Receive
levels for your modem are between -3 and +11 dB *or* an RX of between -3 and
+11. The TX is the level which the modem must transmit for the signal return
to the headend. Acceptable Transmit levels a Terayon modem should be sending
are between 35 and 59 dB.
Your modem will be at maximum performance with an RX of 5 and a TX of 47. If
the RX is below -4 than there may be another case of crappy Shaw stuph. Oh,
and heres a side note, the lower a RX level goes, the higher a TX goes. [RX -8
will mean about TX of 72.]
Introduction
------------
This is mainly for Terayon modems under Shaw. Sure it may be helpful with
motorola modems, but mainly Terayon.
Thanks, Shaw, for throwing out the kewl-e-o RF Technical Field Guide, and
putting an unlocked chain over the dumpster for a couple of hours won't keep
phreaks out! Oh, there was another faction that promoted ignorance too, nazis.
As far as I can tell, not much different from Shaw and Telus...
@HOME RF Concepts
------------------
Here is an example of a partial open problem in which the forward levels
are all within acceptable limits: Ch 2 / 2dB, Ch 6 / 5dB, Ch 14 / 19dB,
Ch 27 / 10dB, Ch 70 / 12dB. Opens are caused by crappy Shaw stuph. We'll
use this as an example for this section.
The main problem the open will cause to a cable modem can be seen in the
signal roll-off in the return path. The higher the frequency or channel, the
better signal can jump across a partial open connection. When the frequency
gets lower, the roll-off is more pronounced.
The example, shown above, has 2 elements acting upon it: RF power level and
the severity of the partial open. If the RF power level were 10dB lower, we
would normally see problems with Channels 2-6 while the higher channels would
appear okay. However, if the partial open were more severe, the roll-off would
also occur at higher channels.
It is important to know that a cable is only an RF convertor for computers.
The signal from the headend [forward path] arrives at frequency just below
Channel 14 while the singal from the headend from the computer [return path]
is below Channel 2 at 24MHz.
Modem Light Sequences
---------------------
Understanding the modem light sequences will help you understand what the hell
your modem is up to. First, here is a key of what my abbreviations will look
like: [You know, the 4 l'il lights on the front right of the modem]
+----+-----------------+ Oh, new and old modems lights will be different.
| NL | No Light | New modems lights will go from left-to-right:
| SG | Solid Green | Send, Receive, Message, Online; while old modems
| BG | Blinking Green | go: Send, Receive, Online, Power.
| SR | Solid Red |
| BR | Blinking Red |
+----+-----------------+
Two more things to remember:
1. If the Online is not solid green than you can't go on the internet.
2. Red lights are evil. [Duh!]
Below are typical light sequences and what they mean.
Online:
+----+----+----+----+ Normally this means you're online, but if your modem is
| NL | NL | NL | SG | really messed, and getting this, then you may be getting
+----+----+----+----+ packet loss or bad connections due to RF issues.
No Return:
+----+----+----+----+ This means the modem has failed to find a return path
| BG | BG | NL | SR | to the headend. Shaw's faulty equipment or low RF
+----+----+----+----+ level's are probaly causing this.
No Signal:
+----+----+----+----+ This means their is no signal getting to the modem
| BG | BG | NL | NL | either due to more crappy Shaw ---- or more RF issues.
+----+----+----+----+
Boot Failure:
+----+----+----+----+ This one is simple, your modem cannot POST [Power On
| NL | NL | SR | SR | Self Test]. Try another power supply, if that don't work
+----+----+----+----+ you're gonna go to Shaw and get yourself a new modem.
No Traffic Contract:
+----+----+----+----+ When a modem attempts to conect to the network but fails
| BG | BG | NL | BG | it will blink 3 green like the top chart. After 15-30
+----+----+----+----+ minutes of failing, the modem will give up and blink 4
| BR | BR | BR | BR | red. This problem might happen if you transfer your
+----+----+----+----+ account or if your modem gets ----ed.
Boot Sequence: [What the lights will be like while booting]
+----+----+----+----+-------------------------------------+
| NL | NL | NL | SG | Power On Self Test |
+----+----+----+----+-------------------------------------+
| BG | BG | NL | NL | Scanning for Forward Signal |
+----+----+----+----+-------------------------------------+
| SG | BG | NL | NL | Scanning for Return Signal |
+----+----+----+----+-------------------------------------+
| SG | SG | NL | NL | Locked onto Signal |
+----+----+----+----+-------------------------------------+
| SG | SG | BG | NL | Registering on Teralink |
+----+----+----+----+-------------------------------------+
| BG | BG | NL | BG | Not Authorized for Connection |
+----+----+----+----+-------------------------------------+
| NL | NL | NL | SG | Modem Online |
+----+----+----+----+-------------------------------------+
| BG | BG | NL | SG | Computer Connecting to Internet |
+----+----+----+----+-------------------------------------+
Modem Levels
------------
There is a webpage, called "Krusty", that cable modems report their RF signal
levels to. The page is located at members.home.net/shawtech, however, it
requires a password and username to login, and I'm not going to give that out.
Lets just pretend you made a few smart calls, or trashed at the right time and
got a login username and password.
You login and navigate your way to the Terapro Level Test page. [Yup, there is
one for Motorola modems too!] Once there, choose the Teralink [Router] your
modem is located on and enter your serial number. [You may have to do trial
and error or social enigineering to get those.] Initiate the modem test and
this is what will be displayed:
+------+---+-------+--------+--------+-----+----------+----------+---------+
|Serial|VCI|Receive|Transmit|Software| PC | Time |Downstream|Upstream |
|Number| | Level | Level |Revision|Light|Registered| S/N ratio|S/N ratio|
+------+---+-------+--------+--------+-----+----------+----------+---------+
| * | | | | | | ** | | |
| |32 | 3.0 | 50.0 | 1.84 | On | | 29.0 | 20 |
| | | | | | | | | |
+------+---+-------+--------+--------+-----+----------+----------+---------+
* your serial number, I didn't have enough space to display it though.
** It'll say it by the days, hours, minutes, and seconds, I just didn't have
enough space to display that either.
Okay, so it won't really look that crappy, but you get the idea. The important
info is Serial Number, Receive Level, Transmit Level, Time Registered as well
as Down and Up Stream Signal to Noise Ratio. VCI, Software Revision and PC
Light aren't important.
Receive [RX] and Transmit [TX] levels are important, as I said before. The RX
are roughly the same as the levels on Channel 14 and mirror the levels the
modem receives. Therefore, an RX of 10 = 10dB @ Channel 14. Acceptable Receive
levels for your modem are between -3 and +11 dB *or* an RX of between -3 and
+11. The TX is the level which the modem must transmit for the signal return
to the headend. Acceptable Transmit levels a Terayon modem should be sending
are between 35 and 59 dB.
Your modem will be at maximum performance with an RX of 5 and a TX of 47. If
the RX is below -4 than there may be another case of crappy Shaw stuph. Oh,
and heres a side note, the lower a RX level goes, the higher a TX goes. [RX -8
will mean about TX of 72.]