Third party equipment connection to a Definity PRI

[BikeTours]

I work for an application service developer who makes a product that is accessed through a telephony interface. Our product is installed in a server that supports a telephony board. The telephony board connects to the customer equipment, a PBX of some kind. Generally we connect to the customer equipment across a T1 interface - T1 robbed bit or ISDN PRI, with PRI being preferred.

Our telephony board provider recommends that in production mode their boards be set to be ISDN user side an to slave clock from the line. In that regard we would want the Avaya PRI to be master clock and ISDN Network-side protocol.

There seems to be a fair amount of information on-line from which one can conclude what would be required on the Avaya side to provide an ISDN connection towards us, what I am missing however is the clocking.

I have yet to come across information that specifically states how a T1 robbed bit or T1-PRI circuit out of the Avaya is optioned to be the master clock on that circuit.

Any suggestions on how you set this T1 trunks to be master clocks?

 

[phonesrus]

The telephony board would need to have, or be optionable to receive clock from the T-1 loop, or it would have to be a function of the developed software.
The PBX receives its clocking from the service provider, or from its own internal tone-clock board. The DS1 board configuration sets where the switch is connected to, and always refers to the switch on the OTHER end of the pipe. Therefore, if it is connected to "network" (ie; service provider), then the "network" is the source. The "Sync" command tells the PBX which board is the Prime clocking source, and (if available) backup (secondary) clock source, apart from its own internal clock.
Likewise, if the PBX is connected to another device (downstream) then the PBX refers to the "device" as "user". Conversely, the downstream "device" would refer to the PBX as "network".
In other words, the "upstream" device is always the "Boss" and the "downstream" device is the "Worker" and takes its orders from the "Boss"!

 

[BikeTours]

I am not definitely sure what you are saying in this passage:

"The DS1-board configuration sets where the switch is connected to and always refers to the switch on the other end of the pipe"

I will state my assumptions on how this all fits together and perhaps you can clarify my understanding.

1) It seems the SYNC table in the Avaya determines your clock source, whether you are pulling that off a DS1 line - preferably a DS1 from your service provider - or are using your own internal clock.

2) I assume that this CO derived clock is then distributed across the whole PBX including to the T1 I am concerned about, namely one that is directly connected to a third party telephony board. I assume then that the Avaya side of this circuit will automatically take the PBX clock and clock the line. My telephony board just has to be set to receive clock [which it wants to do].

"the DS1-board configuration" you refer to is I assume the DS1 circuit pack form. I was able to come across some examples - an example of a trunk to a Cisco router and a trunk to the CO. In the first case the Connect Parameter in the DS1 Circuit Pack Form was Line-side and when facing the CO it was Network - that seem to confirm what you are saying. These T1s were both optioned ISDN-PRI and these examples do highlight the confusion.


An ISDN circuit would be optioned either NETWORK Side or USER Side as far as the ISDN protocol is concerned. One end of the ISDN circuit must also be master clock and the other slave.

The CONNECT parameter in the DS1 Circuit Pack Form and the SERVICE TYPE parameter in the Trunk Group Form seem to be affecting these parameters but I am not sure if they are.

When I option the DS1 circuit pack form
CONNECT parameter for LINE-SIDE. Am I setting that side of the circuit to be the ISDN Network side Protocol and clock master to the far end of the circuit?

Similarly if I Option CONNECT: NETWORK. Am I setting that side of the circuit to be the ISDN USER side protocol and clock slave?

Question 1: In other words is the single parameter in the DS1 Circit Pack form setting both ISDN protocol and clocking?

Question 2: On the Avaya can you even clock from something like my telephony board on a directly connected circuit of this type when the main PBX is clocking from Central Office Lines?

Question 3: Does the Service Type Parameter in the Trunk Group Form have any relevance. All examples I could find had this parameter set to SERVICE TYPE: TIE.


Thanks for responding.

 

[phonesrus]

Consider that a telephone system is like a corporation: The carrier is the CEO, the ultimate master; The PBX is the president of the company, able to make decisions, but must follow the CEO's orders; Next would come servers/devices, the vice-presidents. they have a specific job to do, but always under the presidents control, and so on.
When you look down the chain of devices, they are the users or lineside (receive clock), when you look up the chain they are the network or host (provide clock).
As I said before settings refer to what is on the receiving end.
In the trunk group you refer to "connect" to "network" as the CEO because it is the highest authority. The setting "Tie" is basically for the subordinate chain of command: two devices "tied" together ie; PBX to Server is service type "Tie". The same for two PBX's linked together "Tie"
The clocking is always there you just have to get in "sync" with it. A boss provides clocking, a subordinate receives clocking!