Instaling MICA modems

[johnleeee]

Hi all,

I need help with MICA modems. When I instal them to for example AS 5300 or 3640 what relationship is between router, modems and exchange to which I want connect my PRI/E1 or T1. I mean what is DCE, DTE, CSU/DSU. What is difference between data and voice calls related to handling with mica modems.

Another question is about PRI interface. I know that

PRI/E1 has 30B channels and 1 D channel.And I know that 0 channel is for synchronization and channel 16 is for signalization.But interface on router for signalization is numbered for example 0:15 and I can configure controller e1 with command pri-group timeslots 1-31. So Im little bit confused about numbering channel in real manner.

[makchitale]

MICA are internal digital modems that have connectivity thru the T1/T1/T3/E3 lines which are connected to the telco. For eg, we have a T1 with MICA modems, for an incoming call the telco switch will guide the call to the Access server (5300/3640) which will guide it to the modems if it’s an analog call (for a T1/PRI, we will need “isdn incoming-voice modem” configured under the D channel).

The router is the DTE & the modems are the DCE devices, since they are internal modems we have a virtual RS232 connecting between them (it’s basically just in software & no physical RS232 cable).

http://www.cisco.com/en/US/tech/tk801/tk36/technologies_tech_note09186a008009478d.shtml

The CSU/DSC is built-in in the controller card (T1/E1) that connects the router to the telco switch.

Thanks, Mak

[johnleeee]

Hi Mark,

thanks for explanation.

What about when I have NT1 from provider instaled.

Can I connect CSU/DSU (E1/T1) directly to NT1 or have to always connect T1/E1 to my exchange. NT1 is CSU/DSU too I think.

Another one really important for me is. Im reading

CCNP book about RAS and there stands that slot 0 has reserved lines 1-32 (tty) slot 1 has reserved lines 33-64 and so on. 32 lines in each slot. But I really don understand why 32 when mica modems in module is only 30.

rg

jl

[makchitale]

NT1 is for BRI interface, typically the Cisco T1/E1 controller cards have built-in CSU/DSU, the cable from the demarc needs to be connected directly to the controller card.

Traditionally the async interfaces and lines have been numbered linearly. With a modular platform it was better to fix the line number range to each slot, rather than have it change when adding or removing a NM. The range needed to be 32 to accommodate the NM-32A. At least this means the config doesn't change when async lines are added or deleted from other slots.

In general the line numbers are calculated based on slot numbers (the slot numbers are 0,1..6 based on the platform)

Start line number = ( * 32) + 1

http://www.cisco.com/en/US/products/hw/routers/ps274/products_tech_note09186a00801ca70b.shtml

Thanks, Mak

[johnleeee]

Thank Mak,

So if Im clear after your answer:

each device has dedicated 32 tty lines but only

these are activated which have hardware support

So for example if I have only NM with 30 MICA modems

instaled in slot 3 I will see in show line command

only tty 97-126 but with NM-32A I will see 97-128.

rg

jl

[makchitale]

That's correct.

Thanks, Mak