Norstar MICS 7.1XC: How Many BRIs Possible?

[howdydoo]

I know they have to go in the core cabinet or in the top 2 trunk modules (#s 8 or 7), but what's the max number of BRI-U4 cards the system can host? My system seems to go a little crazy when I try to turn-up the 9th or 10th BRI loop. I would like to be able to serve around 16 or 20 LTs~NTs.

The documentation is either silent or ambiguous on this subject.

Why do I need all these at this late date, you ask? To provide remote extensions (FXSs) from the Norstar, with caller-id, at remote mountain-top ham repeaters.

(This is my first posting here.) Thank you.

 

[curlycord]

Was puzzled as to why it would not mention, never touched BRI but I found this in the sysmgr guide...

"Your Modular ICS allows connection of eight Basic Rate Access loops (four 2B+D channels)"

So looks like 2 BRI-U4's are the max.

Never seen one installed here so not much help on this.




=----(((((((((()----=
curlycord

http://www.curlycord.com

Toronto Canada

http://www.telcopc.ca

 

[norstarboy125]

Maybe one of the UK guys can help you out with this one, here in the US we use PRI not BRI.

Charm City Communications

http://www.charmcitycommunications.com

 

[Multimedium]

I was curious about this, too.

Depending on your system configuration, BRI-ST, BRI-U2, BRI-U4, the off-core DTI cards can only reside in certain trunk modules. In a midi system, the cards must be in trunk modules 3 or 4, for a maxi or mega system, the cards must be in trunk modules 7 or 8. The cards can reside in the ICS regardless of system size.

So, BRI trunk cartridges can be put in the KSU and the two first trunk modules. This allows up to 32 loops (64 B-channels): 8 loops (16 B-channels) in the KSU and 12 loops (24 B-channels) in each trunk module. In other words, that is 8 cartridges: 2 cartridges in the KSU and 3 cartridges in each trunk module.

Also, each loop can be configured as LT or NT. (LT stands for Line Termination. A LT connects to devices, such as telephones. NT stands for Network Termination. A NT connects to the network, so it is basically a line.) However, as curlycord found, a maximum of 8 loops (16 B-channels) can be used as NT. These loops are numbered 201 to 204 and 225 to 228 in profiles 1, 3 and 4; they are numbered 201 to 204 and 231 to 234 in profile 2.

I have never work on a BRI myself, so I can't really say much more.

 

[howdydoo]

Everybody,

Thank you for responding on this arcane subject. After all, who wants to use a bunch of BRIs 25 years after they were the hot way of connecting to the Internet? For me they were always the poor's man's PRI: a way of getting high-quality voice trunks from P*B in the rural area where I live. The alternative was POTS: 12dB of loss to the CO and so noisy, esp after rain, that you could not have a conversation.

Now I use them for that and also a way of sourcing FXSs from the Norstar. I cannot think of another way of doing this; the Norstar does not support FXS over T1, only FXO, DID, & E&M. So I use a BRI loop for this purpose, wired to an Adtran Atlas 550, which makes the conversion to FXS. You get caller ID and can assign incoming lines at the Norstar, just as if it were a Norstar phone. Please let me know if this might solve a problem for you, and I'll give you the details.

Back to the original question: how many BRI loops can you connect to a MICS?

Curlycord cites the System Coordinator Guide:

Your Modular ICS allows connection of eight Basic Rate
Access loops (four 2B+D channels) that can be used for fully
digital connections to ISDN networks and devices. Loops are
connections between the ICS and devices or between the ICS
and the network.

This is the ambiguity I was referring to in my original query. 8 BRI loops equal 8 2B+Ds, not 4. So do they mean 8 BRIs? That would seem to be the case. And why is this crucial limitation found in the Sys Coord Guide and not in the Installer Guide?

I have 11 BRIs (qty 11 2B+D loops on qty 3 ISDN U4 cards) working on an experimental basis with no alarms. It's when I turn up ckts on the 4th card that I start getting alarms, and the system response slows to a crawl:

Alarm 73
Alarm 72-020280
Alarm 72-020290
Alarm 72-020200
Alarm 372-0

It would be nice to be able to exactly decode these, they would probably be a key to what's going on. It seems to be some sort of adverse interaction with the either the PRI or T1 card in Module 2 (MICS core cabinet). The alarms have to do with clock source and D-channel Layer 2 (TEIs).

So I guess I'm getting to be the Norstar BRI expert now. I will advise if I get to the bottom of this.

Thank you again.

 

[curlycord]

372: CC_MSTR_CHG P2 'E' NetLog TestLog
372: | CAUSE:
372: | This logevent is generated whenever the clock
372: | control server switches the clock master, i.e.
372: | from primary to secondary and vice versa or
372: | tracking is re-established on one of the clock
372: | sources.
372: | The parameter indicates the new clock source :
372: | 0 - Tracking on primary
372: | 1 - Tracking on secondary
372: | ENVIRONMENT:
372: | This event can occur for a variety of reasons.
372: | The intent is to provide indication that tracking
372: | has changed or re-established. This is important
372: | for data applications.
372: | HUMAN ACTION:
372: | Unless the problem is due to the customer, e.g.
372: | unplugging the digital link, the customer should
372: | contact the installer.


Alarm code: 73

Reset:
No
Description:
Timing has been lost on T1 or BRI. CSU is freerunning.


72 critical Core
Telephony
Core Telephony -
TEI request on
ISDN device on
system.
Disconnect all
station side ISDN
devices. If problem
persists contact
your local support
group.

=----(((((((((()----=
curlycord

http://www.curlycord.com

Toronto Canada

http://www.telcopc.ca