FXO and PRI question

So as I've learned, a T1 card will not necessarily also be a PRI card. The T1s I have are not PRIs.

Question 1:
SO I need some PRIs ... looks like this is what I'm looking for for my 2600xm routers?:
Cisco 2-Port T1/IDSN Network Adapter, NM-2CT1-CSU

Question 2:
Once I get some PRIs, do I just make an T1 crossover cable and connect them and then I can program and send calls between routers by the connected PRI links? Then for my PSTN router to connect to HQ, BR1, and BR2, the PSTN router would need 3 PRI cards and each site would need one PRI card? Am I headed in the right direction here?

Question 3:
I'm wondering if I can connect an FXO to an FXO? I'm guessing Not. But could I have a call go out one router's FXO port and into a neighbor routers FXS port? I dont know why or how this would be useful just something I was thinking about....

Thanks

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astorrs

rchase wrote: »

Question 1:
SO I need some PRIs ... looks like this is what I'm looking for for my 2600xm routers?:
Cisco 2-Port T1/IDSN Network Adapter, NM-2CT1-CSU

Or you could go with the VWIC equivalent: VWIC-1MFT-T1 ( or VWIC-2MFT-T1, etc.) and keep your NM slot free for other things.

rchase wrote: »

Question 2:
Once I get some PRIs, do I just make an T1 crossover cable and connect them and then I can program and send calls between routers by the connected PRI links? Then for my PSTN router to connect to HQ, BR1, and BR2, the PSTN router would need 3 PRI cards and each site would need one PRI card? Am I headed in the right direction here?

Making sense to me (keep in mind for HQ you can buy cards with multiple ports). Unless you have an ISDN switch/simulator lying around or money to waste on one.

rchase wrote: »

Question 3:
I'm wondering if I can connect an FXO to an FXO? I'm guessing Not. But could I have a call go out one router's FXO port and into a neighbor routers FXS port? I dont know why or how this would be useful just something I was thinking about....

I'd use an FXO on your primary HQ router and connect it to an analog phone line (assuming you have one), then once your branch office routers are working (with the PRI links between BR1/BR2 and HQ), using a phone "located" at BR1 and/or BR2 call your cell phone, etc.

pitviper

Q1. The NM-2CT1-CSU will not work for voice. You’ll need a VWIC installed in one of the various NM-HDV modules, or a combination of VWIC and AIM-VOICE-30 module.

Q2. You can simulate a voice PRI between 2 routers with a T1 x-over cable assuming that they both have the appropriate VWIC and DSP hardware. Yes, you are on the correct path with the PSTN router.

Q3. To simulate a POTS connection, you can go FXS (PSTN Cloud side) -> FXO.

Do a quick search on the forum for “PSTN Cloud” lots of good examples to get you started.

rchase

Awesome! thanks for your input guys. Looking fwd to getting this PSTN 1760 setup with 3 VWIC PRIs

azaghul

From memory, the way you setup clocking on the 1760's is "interesting". I replaced mine mid-year with 2801's, a lot easier.

Also, I think the 1760's only support 2 x PRI (and are WIC slot dependant), the rest have to be set up as CAS.

rchase

azaghul,

I also read that 1760 only supports 2 x PRI...

At this point I'm not sure I want to invest in the 1760 as my PSTN... considering buying the 2801

azaghul

If you can, I'd go for a 2811 as PSTN, I found (after lots of troubleshooting, then reading the docs) the 2801 is HWIC slot dependant for VWICs....

rchase

2801 has 2 HWIC slots .. thats enough for my PSTN router. I'll just have one slot be a 2VWIC and the other a 1VWIC

pitviper

+1 for the 2811 - the 2801 is obnoxiously loud LOL

astorrs

pitviper wrote: »

+1 for the 2811 - the 2801 is obnoxiously loud LOL

Really, are you sure yours wasn't broken? The 2801 should run quieter than a 2811.

shodown

my 2801's are loud as hell.

astorrs

shodown wrote: »

my 2801's are loud as hell.

I didn't mean to say they were quiet - they're way louder than 2600's, etc., but compared to a 2811 they should be in a slightly quieter area of hell.

pitviper

astorrs wrote: »

Really, are you sure yours wasn't broken? The 2801 should run quieter than a 2811.

I've deployed plenty of the them - and they are MUCH louder then the 2811 after they boot. (And I'm really not one to complain about noise LOL)

And for reasons that are foreign to me, the 2801 seem to have a much higher failure rate. I’ve switched out a bunch of production units because of system bus/memory errors which I typically don’t see on the “other” 2800s. For that reason the minimum production router we use is the 2811/2911. Not really an issue in a lab, but might be noteworthy. I think I recall a post of someone here going with 2801s because they were able to get a “stack” of them from work which needed repair LOL