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NBX Pri Circuit.

DanCarroll
Frequent Advisor

NBX Pri Circuit.

I have AT&T pri's using 4ess protocal . SDN network assignments,etc



I have 5 circuits grouped together.



This past Thursday the first card stoppped taking calls, and incoming callers got a fast busy.



But the calls did not jump to the second card .



The on-call tech did a system reboot. This did not clear issue and incoming callers were still getting busy signals.



The calls moved to next circuit when the T1 feed cable was pulled.



The card needed to be physically power cycled then circuit restarted normally.



Any thoughts or ideas why the calls did not go to the next circuit?



Or Why the card came up unknown after the reboot?



The fast busy signals were from the carrier not the NBX, I think??



 



 



 



6 REPLIES
bosoxfan_1
Super Advisor

Re: NBX Pri Circuit.

yes, fast busy is from the telco.



Why the calls did not fail over to the PRI card is really a telco issue since they are incoming calls .



As for the card coming up "unknown", this is a network issue. PRI sends Slave status to the NBX



every 30 seconds. If the NBX does not hear from the card in 4 minutes, it then marks the card "unknown".



Without a network trace, we cannot determine root cause of why the card came up "unknown"



merlin_1
Super Advisor

Re: NBX Pri Circuit.

Commonly when a span " goes down " , it is not totally down , sometimes able to process calls / sometimes busy signals , sometimes dead air .  So if the PBX does not look at it as a complete failure it will not fail over . A lot of PBX'es treat this condition the same way .



 



When the NBX came back up after the restart , the card never rebooted . If it did , it would have brought the span back up .



 



So I guess the question is why the card never rebooted ....



DanCarroll
Frequent Advisor

Re: NBX Pri Circuit.

the card said unknown after the reboot of the system.



I had to have the card pulled from the shelf and power cycled to have it reboot.



merlin_1
Super Advisor

Re: NBX Pri Circuit.

I saw that comment in your posting above.....



If it occurs again , that would be the first thing I would check .



Why are you using a 4ESS set up ? Is that all that ATT can provide ?  That means your central office  does nto support a full ISDN circuit ?



Maybe when the PRI went down , The Central Office may be having some difficulty responding . Has the issue occurred since the reboot ?



DanCarroll
Frequent Advisor

Re: NBX Pri Circuit.

its  been fine since the reboot.



My company got the right to use 4ess with sdn, because it was CHEAP.



 



merlin_1
Super Advisor

Re: NBX Pri Circuit.

Sorry to hear that . I thought all 4ESS offices up here were upgraded to at least 5ESS rev10  , but you folks probably were not Verizon when you bought those older circuits .


 



If you can get some info as to why the card did nto reboot , then we can help ....



 



 



Thanks Dan !



 



 



This message was edited by merlin on 4-20-10 @ 12:34 PM