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Feature #4910

open

Automatically set the A / alarm bits in Tx if no signal on Rx

Added by laforge over 1 year ago. Updated 4 months ago.

Status:
New
Priority:
Low
Assignee:
Category:
-
Target version:
-
Start date:
12/16/2020
Due date:
% Done:

0%

Spec Reference:

Description

At least according to one of my German retronetworking books on PDH it is stated that an E1 interface must set the A[larm] bit in TS0 if no received signal is detected.

I expect we don't do that yet as we have no real concept of LOS.

Relying on the host software to insert that A bit is not really a good idea, as the host has the least idea of what's happening on the physical layer.

So I would guess, similar to the way how we automatically can generate the E bits in case of Rx CRC errors, it would be good to generate the A bits based on whether or not we see incoming Rx clock cycles.


Related issues

Related to E1/T1 Hardware Interface (including icE1usb) - Bug #5381: icE1usb DAHDI driver: generate YELLOW alarm towards peerNewlaforge01/02/2022

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Actions #1

Updated by laforge 5 months ago

  • Related to Bug #5381: icE1usb DAHDI driver: generate YELLOW alarm towards peer added
Actions #2

Updated by tnt 4 months ago

Shouldn't the A bit be set if there we don't have alignement ? Not just complete LOS, but any condition causing us to not detect a valid framed signal ?

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