making an E1-FXS interface system for dial-up

[ali6359]

i have a cisco AS5300 RAS for dial-in and i am planing to connect the E1 line to something that takes the E1 signal and interfaces it to FXO, which connects to my PABX and to my client. my question is is what cards are required on the 2600xm to acheive the signaling from E1 to FXO? i would also like the config to get the equipment working.

[Giuseppe Larosa]

Hello Ali6359,

E1 is an ISDN PRI interface and requires to be connected to an ISDN switch.

The FXO interface is a PSTN interface central office is not an ISDN type of interface and requires a PSTN switch.

You should look for an ISDN BRI interface for the C2600XM, so that you would need just an ISDN switch emulator to make calls between the ISDN BRI and the ISDN PRI.

Edit:

Verify if your PABX supports also ISDN interfaces. The router can act as Central office with FXO or as user interface with FXS.

Interworking between ISDN PRI E1 and FXO would require an ISDN switch connected to a PSTN switch.

Hope to help

Giuseppe

[ali6359]

i mean, from as5300 e1 to somthing that changes the e1 to to the analog fxo for my Excelltel pabx then to client

[Giuseppe Larosa]

Hello Ali6359,

>> i mean, from as5300 e1 to somthing that changes the e1 to to the analog fxo for my Excelltel pabx then to client

yes, what I mean is this task is not a router job: you need a PSTN / ISDN switch for this because also signalling is involved (how to make a call to a phone number on the ISDN and on the PSTN) it is not only a question of different interface types.

Hope to help

Giuseppe

[ali6359]

do you know the equipment used for the e1-fxo signaling? i only want to use it for 1 client (myself) because i have an AS5300 i found for almost nothing and want to make a dial-in server for fun.

[Giuseppe Larosa]

Hello Ali6359,

an example of ISDN switch emulator is in the following link

https://www.gl.com/isdnemulator.html

However, I'm not sure it covers also the PSTN switch emulation

This is just to give an idea of what you would need to setup a working lab.

Edit:

see also

http://promptus.com/Patapsco_Liberator.html

this is still an ISDN switch emulator

Hope to help

Giuseppe

[ali6359]

what about using chanelised E1, from the RAS to a router with an E1 card, voice processor module and an FXS card. would it work?

[Giuseppe Larosa]

Hello Ali,

ISDN E1 cannot be connected back to back  like an ethernet interface an ISDN switch would still be in the middle between AS 5300 E1 and router E1 for the signaling (Q921, Q931 and above)

I am not sure that then you can take a B channel and build a VOIP interconnection with a pots dial peer associated to the FXO interface  that is what you would like to do.

Usually VOIP gateway can do the following:

take a POTS or ISDN connection and interconnects it with a VOIP SIP or H.323 IP dial-peer or to an IP phone using Skinny Cisco protocol or SIP.

The two parts are called call legs.

For example to have two VOIP call legs interconnect you need the CUBE ( Unified Border Element) license installed.

Hope to help

Giuseppe

[ali6359]

does this device acheive the signaling? https://www.vconsole.com/product/93 . i know its very expensive but can other hardware be used? probaly the last resort as i cant find anithing i can afford

[ali6359]

can this device acheive the switching/signaling https://www.vconsole.com/product/93 ? i know its expensive but probaly the last resort as i cant find anything affordable.

[Giuseppe Larosa]

Hello Ali,

the device described in the link

https://www.vconsole.com/product/93

can perform the required signalling tasks on ISDN PRI and on PSTN FXS analog line.

However, the price of US $ 2400 is really high !!!!!

If you are doing this just for self study and to use the AS5300 that you have bought I would suggest to give up.

If you have a real need in a production network it becomes a different matter.

Try to see if you find an used one on ebay at  much lower price.

Hope to help

Giuseppe

[ali6359]

i am keeping a very close watch on ebay, although as of now i can find nothing but mabye one day ill find one. $2400 USD is arround $3400 AUD and is just SUPER EXPENSIVE! but i now have an idea on what i am looking for. 

i know VOIP is not really good for dial-in access but i want to experement for fun. can i take the e1 from the RAS and put it on some interface or does it still need the switching equipment? ill just shelf the as5300 until i find anything.

[ali6359]

i can only find ISDN BRI simulators at a low cost on ebay as i cant find any PRI. is it possible to take the PRI from the RAS and convert it to BRI then it goes to a BRI simulator then to a BRI-FXS interface? not sure if this would work but still, would it?

[Giuseppe Larosa]

Hello Ali,

unfortunately to "convert" an ISDN PRI to an ISDN BRI you would need an ISDN switch emulator.

So the answer is negative.

You can look for modules with ISDN BRI that might be installed on the AS5300 or even modules with PSTN ports/modems for AS5300.

Hope to help

Giuseppe

[ali6359]

so if i have a BRI interface on the RAS, can i use this as a bri switch? https://www.ebay.com/itm/Merge-ISDN2000AFP-ISDN-Basic-Rate-Interface-/382433358181?_trksid=p2349526.m4383.l4275.c4#viTabs_0 

i do have a cisco 3825 with digital modems can i get a bri network module and use that?

also, to convert the bri from the switch to fxs, what do i need?