Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

What I need to simulate a PSTN

Hi All,

Working towards me CCIE Voice Lab exam.....

I have 3745 Router with:

1 x NM-HDV

3 x PVDM-12

1 x VWIC-1MFT-E1 Module.

1 x 7960 Phone

I have placed a Loopback cable in the single E1 socket, but I get "RX <- BAD FRAME" received when debug isdn q921 is turned on. So this will not help me simulate a PSTN for me to see Q931 traffic.

Would a single VWIC-2MFT-E1 card be enough to simulate a ISDN q931 and q921 message if I loop the ports together with a E1 crossover and set one as USER and the other NETWORK?

I am trying to go for least cost solution with what I already have?

Thanks,

Ed

Everyone's tags (3)
1 ACCEPTED SOLUTION

Accepted Solutions
VIP Super Bronze

What I need to simulate a PSTN

You need two different routers. You are connecting them back to back. You cant do this on the same router.

You need 1 router acting as PSTN

you need another router acting as the User side

Pls rate useful posts

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
11 REPLIES
Hall of Fame Super Silver

What I need to simulate a PSTN

No, you will need 2 ports and connect them via cross-over T1 cable as well as setup one side as ISDN protocol-emulate network.

HTH,

Chris

VIP Super Bronze

Re: What I need to simulate a PSTN

Hi, here are the configuration you need. As chris said you need a cross over E1 cable to connect the two routers back to back.

The pinout for a corss over e1/t1 is as follows:

1 <-> 4

2 <-> 5

4 <-> 1

5 <-> 2

Router 1 (PSTN SIDE)

controller E1 0/2/0

clock source internal (Because its PSTN side, it is the clock provider)

pri-group timeslots 1-31

description E1 Link to Labrouter 2

interface Serial0/2/0:15
no ip address
encapsulation hdlc
isdn switch-type primary-net5
isdn timer T310 120000
isdn protocol-emulate network (****Simulating PSTN SIDE)
isdn incoming-voice voice
no cdp enable

Router 2 (user side)

controller E1 0/1/1

pri-group timeslots 1-31

description E1 Link to Lab PSTN

interface Serial0/1/1:15

no ip address

encapsulation hdlc

isdn switch-type primary-net5

isdn incoming-voice voice

no cdp

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
New Member

What I need to simulate a PSTN

Thanks guys,

Can I confirm that this can be done on the same route with 1 x 2 port VWIC card?

I understand that I will see both the inbound and outbound q931 messages on the same router.

Thanks,

VIP Super Bronze

What I need to simulate a PSTN

You need two different routers. You are connecting them back to back. You cant do this on the same router.

You need 1 router acting as PSTN

you need another router acting as the User side

Pls rate useful posts

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
New Member

What I need to simulate a PSTN

Thanks guys.

I'll keep a watch out for another voice router going for cheap than,

Hall of Fame Super Silver

What I need to simulate a PSTN

I suppose teaching people how to fish does not go far these days and step by step instructions are much more appreciated :-(

Chris

VIP Super Bronze

What I need to simulate a PSTN

Chris,

+5 for your inputs. I am actually confused as to how to help people on this forum. Should they be fed completely or should you lead them on the proactive approach. I mean sometimes you post a link to a document and people wont even bother reading it, so I share your thoughts...

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
Hall of Fame Super Silver

What I need to simulate a PSTN

Thanks, but you did not rate m y post :-)

VIP Super Bronze

What I need to simulate a PSTN

Now I did..I rated the wrong post

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
Hall of Fame Super Silver

Re: What I need to simulate a PSTN

Surely you can do this on the same router, for studying it will do the job.

Sent from Cisco Technical Support iPhone App

VIP Super Bronze

What I need to simulate a PSTN

Edip,

Chris is right, you can do it on the same router..I got things mixed up. But you need two different ports configured as I explained int he config section

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
2785
Views
24
Helpful
11
Replies