asterisk users - Sep 2004 - Asterisk testbed for teaching connecting to a PRI-ISDN

Hi,
I would like to realize a voip testbed that should simulate the scenario
in which two companies have an asterisk PBX connected through a PRI-ISDN
to the Telco operator.
I have no experience of T1/E1 connection but I think that the above
could be relized with 3 asterisk boxes equipped with Digium TE405P cards.
One of the box will represent the Telco, the other two, the two
companies PBX.
I would like to know if it is needed something between the point-point
connections or it is possible to just cross-connect them.
I need the testbed to be representative of the real-world difficulties
in putting on an Asterisk BOX for connecting to a PRI-ISDN: is other
hardware needed (e.g. echo cancellers or failover switches)?

Asterisk BOX (Simulate the Telco)
with Digium TE405P
   |                   \
   | E1                 \  T1
   |                     \
[What to put here?]   [What to put here?]
   |                       \
   | E1                     \ T1
   |                         \
Asterisk BOX (Company)   Asterisk BOX (Company 2)
with Digium TE405P       with Digium TE405P


Regards,
    Francesco Delfino

You need an E1 back-to-back cable.

Regards,

antonio

Francesco Delfino wrote:
> Hi,
> I would like to realize a voip testbed that should simulate the scenario
> in which two companies have an asterisk PBX connected through a PRI-ISDN
> to the Telco operator.
> I have no experience of T1/E1 connection but I think that the above
> could be relized with 3 asterisk boxes equipped with Digium TE405P cards.
> One of the box will represent the Telco, the other two, the two
> companies PBX.
> I would like to know if it is needed something between the point-point
> connections or it is possible to just cross-connect them.
> I need the testbed to be representative of the real-world difficulties
> in putting on an Asterisk BOX for connecting to a PRI-ISDN: is other
> hardware needed (e.g. echo cancellers or failover switches)?
>
> Asterisk BOX (Simulate the Telco)
> with Digium TE405P
>   |                   \
>   | E1                 \  T1
>   |                     \
> [What to put here?]   [What to put here?]
>   |                       \
>   | E1                     \ T1
>   |                         \
> Asterisk BOX (Company)   Asterisk BOX (Company 2)
> with Digium TE405P       with Digium TE405P
>
>
> Regards,
>    Francesco Delfino
>

On Fri, 10 Sep 2004, Francesco Delfino wrote:
    > [...]One of the box will represent the Telco, the other two, the two
    > companies PBX. I would like to know if it is needed something
    > between the point-point connections or it is possible to just
    > cross-connect them.

As more experienced people prepare to reply, I'd like to give my [highly
theoretical] opinion (I'm still waiting for hardware I ordered):  I think
it is possible to just cross connect them, as long as you get the
signaling right.  In my opinion, the Box simulating the telco should
signal as the network side and the one representing the company should
signal as the customer side...

Hope that makes sense.


Cheers,
Gerald.

Hi Francesco,

you can easily run two Asterisk systems "back to back" in the way you
described below.

  ---------------                             ---------------
 |   Asterisk 1 |                            | Asterisk 2   |
 |        TE405 |==============X=============| TE405        |
 |Provide Clock |      Cross Over Cable      | Take Clock   |
 |          NET |                            | CPE          |
  ---------------                             ---------------

In the diagram above Asterisk 1 is simulating the PSTN (Telco) and Asterisk
2 is a PBX. To set the ISDN protocol correctly for Asterisk 1 your settings
should include pri_net and for Asterisk 2 you should have an entry such as
pri_cpe. To make sure that timing is generated by 1 and received by 2 you
should use the settings below:

Asterisk 1:          span=1,0,0,ccs,hdb3,crc4
Asterisk 2:          span=1,1,0,ccs,hdb3,crc4

The only hardware that you need to interconnect the two systems is a cross
over RJ45 cable, pin out is shown below:

    PRI Cross Over Cable

         2------5
         1------4
         5------2
         4------1

There are plenty of notes on how to achieve your requirements, already
written up by other list contributors; simply check the archive of this
mailing list at: http://lists.digium.com/ or look at the wiki:
http://www.voip-info.org.

Good Luck!

Darren
--
Comgate
Telco>Internet<Broadcast

-----Original Message-----
From: asterisk-users-bounces@lists.digium.com
[mailto:asterisk-users-bounces@lists.digium.com]On Behalf Of Francesco
Delfino
Sent: 10 September 2004 09:07
To: asterisk-users@lists.digium.com
Subject: [Asterisk-Users] Asterisk testbed for teaching connecting to
aPRI-ISDN


Hi,
I would like to realize a voip testbed that should simulate the scenario
in which two companies have an asterisk PBX connected through a PRI-ISDN
to the Telco operator.
I have no experience of T1/E1 connection but I think that the above
could be relized with 3 asterisk boxes equipped with Digium TE405P cards.
One of the box will represent the Telco, the other two, the two
companies PBX.
I would like to know if it is needed something between the point-point
connections or it is possible to just cross-connect them.
I need the testbed to be representative of the real-world difficulties
in putting on an Asterisk BOX for connecting to a PRI-ISDN: is other
hardware needed (e.g. echo cancellers or failover switches)?

Asterisk BOX (Simulate the Telco)
with Digium TE405P
   |                   \
   | E1                 \  T1
   |                     \
[What to put here?]   [What to put here?]
   |                       \
   | E1                     \ T1
   |                         \
Asterisk BOX (Company)   Asterisk BOX (Company 2)
with Digium TE405P       with Digium TE405P


Regards,
    Francesco Delfino

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-----Original Message-----
From: asterisk-users-bounces@lists.digium.com
[mailto:asterisk-users-bounces@lists.digium.com]On Behalf Of Begumisa
Gerald M
Sent: 10 September 2004 12:45
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [Asterisk-Users] Asterisk testbed for teaching connecting
to aPRI-ISDN


      On Fri, 10 Sep 2004, Francesco Delfino wrote:
    > [...]One of the box will represent the Telco, the other two, the two
    > companies PBX. I would like to know if it is needed something
    > between the point-point connections or it is possible to just
    > cross-connect them.

As more experienced people prepare to reply, I'd like to give my [highly
theoretical] opinion (I'm still waiting for hardware I ordered):  I think
it is possible to just cross connect them, as long as you get the
signaling right.  In my opinion, the Box simulating the telco should
signal as the network side and the one representing the company should
signal as the customer side...

Hope that makes sense.


Cheers,
Gerald.
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Asterisk-Users@lists.digium.com
http://lists.digium.com/mailman/listinfo/asterisk-users
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