cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

TR-08 T1 Signalling Bits

TR-08 T1 Signalling Bits

Article ID: 1605
Q&A

  TR-08 T1 Signalling Bits


Q:

TR-08 T1 Signalling Bits

A:

Introduction

Signaling bits are used to indicate the progress of a voice call on a T1 circuit (Off-hook, On-hook, Ringing, Disconnect, etc...) These apply if you are using ADTRAN FXS/FXO/E&M voice modules. This note will explain the states of the signaling bits.

Signaling Bit Charts

Single Line Party

(Loop Start)

System Status

TXA

TXB

RXA

RXB

Comments
On-hook/IDLE0011Idle mode on T1 and 2W
Off-hook on 2W10112W side is off-hook
Call Complete1011Both 2W side and T1 is off-hook
Incoming ringing0011/0T1 tells us to output ringing voltage
Far End Disconnect----10Far end has went back on-hook; should pull battery, but 750 FXS and TSU FXS do NOT!
Reverse Battery----1/01/0Telco tells us to reverse battery; only valid when Answer Supervision enabled
Unequipped11----No card installed; not mapped
Channel Test----01Telco has channel in a test mode
Universal Voice Grade

(UVG - Loop Start)

System Status

TXA

TXB

RXA

RXB

Comments
On-hook0001/02W and T1 are on-hook
Off-hook on 2W1001/02W side is off-hook
Call Complete1001/0Both 2W side and T1 is off-hook
Incoming ringing0011/0T1 tells us to output ringing voltage
Far End Disconnect----00Far end has went back on-hook; pull battery from 2W
Reverse Battery----1/01/0Telco tells us to reverse battery; only valid when Answer Supervision enabled
Unequipped11----No card installed; not mapped
Channel Test----01Telco has channel in a test mode
Universal Voice Grade

(UVG - Ground Start)

System Status

TXA

TXB

RXA

RXB

Comments
On-hook00002W and T1 are on-hook; 2W TIP OPEN
Ring ground01002W side detects ring ground
Tip ground return0101/0Tip ground return detected from T1 side
Off-hook/Loop closure1001/02W side detects loop closure
Call Complete1001/0Connection established
Incoming ringing----11/0T1 tells us to output ringing voltage
Far End Disconnect----00Far end has went back on-hook; pull battery from 2W (TIP OPEN)
Reverse Battery----1/01/0Telco tells us to reverse battery; only valid when Answer Supervision enabled
Unequipped11----No card installed; not mapped
Channel Test----01Telco has channel in a test mode

If you experience any problems using your ADTRAN product, please contact ADTRAN Technical Support.

Labels (1)
Version history
Revision #:
1 of 1
Last update:
‎03-02-2012 07:03 AM
Updated by:
 
Contributors