On Mon, 2009-01-19 at 11:10 +0100, Lukas Rypl wrote: > I am missing any description of zaptel/DAHDI alarms. The TE200 series > user manual contains only a description of LEDs states. These alarms > states are visible in zttool/dahditool or in astersick CLI (zap show > status) and I wonder what is the real meaning of these alarms for E1 > channel.
I can't speak for all the possible states in the T1/E1 card driver, but I can state that typically in T1s and E1s you have three different general alarm states: RED alarms, YELLOW alarms, and BLUE alarms. (This is a brief synopsis of the information we cover in the Asterisk Advanced training class.) Red alarm --- Your T1/E1 port will go into red alarm when it maintain synchronization with the remote switch. A red alarm typically indicates either a physical wiring problem, loss of connectivity, or a framing and/or line-coding mismatch with the remote switch. When your T1/E1 port loses sync, it will transmit a yellow alarm to the remote switch to indicate that it's having a problem receiving signal from the remore switch. (The easy way to remember this is that the R in red stands for "right here" and "receive"... indicating that we're having a problem right here receiving the signal from the remote switch.) Yellow alarm or RAI (Remote Alarm Indication) --- Your T1/E1 port will go into yellow alarm when it receives a signal from the remote switch that the port on that remote switch is in red alarm. This essentially means that the remote switch is not able to maintain sync with you, or is not receiving your transmission. (The easy way to remember this is that the Y in yellow stands for "yonder"... indicating that the remote switch (over yonder) isn't able to see what you're sending.) Blue alarm or AIS (Alarm Indication Signal) --- Your T1/E1 port will go into blue alarm when it receives all unframed 1s on all timeslots from the remote switch. This is a special signal to indicate that the remote switch is having problems with it's upstream connection. As far as I know, dahdi_tool/zttool and Asterisk don't correctly indicate a blue alarm (at least I've never seen them indicate one). The easy way to remember this is that streams are blue, so a blue alarm indicates a problem upstream from the switch you're connected to. I hope the explanation helps. -- Jared Smith Digium, Inc. | Training Manager _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
