E1 PRI (ISDN) - Reset Procedure
Steps in RED apply to clocking, omit on large systems, or see below for media gateway info
A Primary Rate Interface (PRI) comprises 3 components, maintained in 2 loads:
- Voice channels, and clock: LD 60, associated data channel (DCH): LD 96.
1 LD 60: STAT
Note the LOOP number, and associated DCH (on channel 31) of your PRI. We must know these before we start!
The following STAT shows Loop 12 and DCH 5, but you must substitute YOUR values in the commands!
.stat ⇐ in LD 60 PRI2 LOOP 12 - ENBL ⇐ Loop number REF CLK: ENBL SERVICE RESTORE: YES ALARM STATUS: OOS CH 01 - DSBL DID VOD * CH 02 - DSBL DID VOD * ⇐ all channels are down CH 03 - DSBL DID VOD * CH 04 - DSBL DID VOD * : CH 31 - DCH 5 ⇐ D channel for this PRI shown at CH 31
2 Disable:
Overlay | Commands | Notes |
---|---|---|
LD 96: | DIS AUTO 5 | disable auto recovery |
DIS DCH 5 | disable d-channel | |
STAT DCH 5 | confirm d-channel is disabled | |
LD 60: | DISL 12 | disable loop |
STAT 12 | confirm loop is disabled | |
DIS CC 0 | CC 0 for Option 11, loop & shelf of clock controller for MGCs |
For a plain circuit 'bounce' or reset count to 10, and re-enable it.
To remove / replace card, also disable the associated MSDL:DIS MSDL x
(MAP DCH
to identify MSDL).If the PRI card has a front panel switch, set it to Dis before removing/inserting card. On inserting, wait 10 seconds: set to Enb.
Check a replacement cards dip switches. UDT cards are generally NOT drop-in swap-able, as they must always be configured.
3 Enable:
Overlay | Commands | Notes |
---|---|---|
LD 60: | ENLL 12 | enable loop, this should also enable DCH 5, if not, see below |
ENL CC 0 | CC 0 for Option 11, loop & shelf of clock controller for MGCs | |
TRCK PCK | set track 'primary' reference, add loop & shelf for MGCs | |
STAT 12 | confirm that loop is enabled | |
LD 96: | STAT DCH 5 | confirm d-channel is enabled, if not: ENL DCH 5 |
ENL DCH 5 | enable d-channel, wait for 'DCH: 5 EST' message | |
ENL AUTO 5 | enable auto d-channel recovery (eg, after a line failure) | |
LD 60: | STAT 12 | confirm status, all channels should be IDLE |
There should now be 3 green lights on the card (if the card has a clock controller), and 30 IDLE channels!
From the STATus output, make sure the REF CLK is enabled, and tracking (may take a few mins) see below.
LD 60: | RCNT 12 | reset loop error counters after a reset, use LCNT to list counters... |
LCNT 12 | list loop error counters, use to help identify a problem, eg: frame slips |
If this procedure doesn't work, try the following:
- LD 96:
DIS SERV 5
This will prevent PTT DCH service messages from MBSYing the channels. - LD 96:
DIS MSDL x (ALL)
,ENL MSDL x (ALL, FDL)
UseMAP DCH
and/orSTAT MSDL
to find x.
If the loop is 'stuck', and you are unable to disable/enable it, try to reset the DCH: in LD 96, enter: RST MSDL 5
If you have problems bringing a PRI back into service, refer to 2.0 Mb PRI Maintenance.
A note about clocks:
Each PRI needs a reference clock, which can be either Tracking or Free-run (non-tracking). With Media Gateways, each shelf (with digital services) requires a clock controller daughter board on one PRI card (often the left most card). Print SYTI (or DDB) in LD 73 to list them. If you're not sure in which physical loop/shelf a PRI is located, print CEQU
in LD 22. For an Option 11, the clock is: CC 0
Clock controller comands in LD 60:
ssck l s
- check status of clock controller in media gateway: l=loop; s=shelfenl cc l s
/dis cc l s
- enable/disable the clock controller in media gateway: l=loop; s=shelftrck aaa l s
(aaa = PCK, SCLK, or FRUN) - track shelf to the primary or secondary reference, or enable free-run.
If you experience excessive slips after a PRI outage (DTA103 errors), its very likely that the clock controller is either disabled, or has switched to free-run, when it should be tracking. It's good practice to always check the clock status after a circuit returns to service.
For more information about UDT card Clock Controllers, refer to UDT E1 T1 Clocks.
Example printouts:
Use STAT in LD 60 to indentify your PRI Loop(s), DCH number(s), and check the circuit status.
The CH31 position shows the associated D-channel number for that loop, in this case DCH 5.
A healthy 'In Service' E1 may look like this:
- Loop is enabled, clock in enabled (and tracking), no alarms indicated, all voice channels are idle.
.stat 12 PRI2 LOOP 12 - ENBL circuit/loop is enabled REF CLK: ENBL reference clock is enabled TRACKING loop is tracking the reference clock SERVICE RESTORE: YES ALARM STATUS: ACCEPTABLE no alarms CH 01 - IDLE DID VOD * CH 02 - IDLE DID VOD * all channels are idle CH 03 - IDLE DID VOD * CH 04 - IDLE DID VOD * CH 05 - IDLE DID VOD * CH 06 - IDLE DID VOD * CH 07 - IDLE DID VOD * CH 08 - IDLE DID VOD * CH 09 - IDLE DID VOD * CH 10 - IDLE DID VOD * CH 11 - IDLE DID VOD * CH 12 - IDLE DID VOD * CH 13 - IDLE DID VOD * CH 14 - IDLE DID VOD * CH 15 - IDLE DID VOD * CH 16 - IDLE DID VOD * CH 17 - IDLE DID VOD * CH 18 - IDLE DID VOD * CH 19 - IDLE DID VOD * CH 20 - IDLE DID VOD * CH 21 - IDLE DID VOD * CH 22 - IDLE DID VOD * CH 23 - IDLE DID VOD * CH 24 - IDLE DID VOD * CH 25 - IDLE DID VOD * CH 26 - IDLE DID VOD * CH 27 - IDLE DID VOD * CH 28 - IDLE DID VOD * CH 29 - IDLE DID VOD * CH 30 - IDLE DID VOD * CH 31 - DCH 5
An 'Out Of Service' E1 may look like this:
- A RED alarm on the card face plate, and a LOS 'loss of signal' in STAT indicates a circuit problem (no receive).
.stat 12 PRI2 LOOP 12 - ENBL REF CLK: DSBL SERVICE RESTORE: NO ALARM STATUS: OOS NO AUTO STRT LOCAL ALARM : LOS out of service, with loss of signal CH 01 - MBSY DID VOD * CH 02 - MBSY DID VOD * all channels are down CH 03 - MBSY DID VOD * CH 04 - MBSY DID VOD * CH 05 - MBSY DID VOD * CH 06 - MBSY DID VOD * CH 07 - MBSY DID VOD * CH 08 - MBSY DID VOD * CH 09 - MBSY DID VOD * CH 10 - MBSY DID VOD * CH 11 - MBSY DID VOD * CH 12 - MBSY DID VOD * CH 13 - MBSY DID VOD * CH 14 - MBSY DID VOD * CH 15 - MBSY DID VOD * CH 16 - MBSY DID VOD * CH 17 - MBSY DID VOD * CH 18 - MBSY DID VOD * CH 19 - MBSY DID VOD * CH 20 - MBSY DID VOD * CH 21 - MBSY DID VOD * CH 22 - MBSY DID VOD * CH 23 - MBSY DID VOD * CH 24 - MBSY DID VOD * CH 25 - MBSY DID VOD * CH 26 - MBSY DID VOD * CH 27 - MBSY DID VOD * CH 28 - MBSY DID VOD * CH 29 - MBSY DID VOD * CH 30 - MBSY DID VOD * CH 31 - DCH 5