Simulate PRI line 2600 series router

[david.sharp]

Hi Cisco

I wonder if some one could provide me with some help and advise.

I am attempting to setup a lab network with some old equipment that has been decommissioned but is still functional.

I have an old Tandberg ISDN gateway and a Cisco 2620xm router running a voice IOS, I also have a nm-hdv (yep with the PVDM-12) with a e1 card in.

what i am attempting to do at the moment and struggling with, is to setup the link between the IOS router and the tandberg gateway in order to be able to simulate an ISDN call out a H.323/SIP network via the ISDN gateway to the 2600 router, which I will then similate an external network using CME ( I hope having to do nothing more than a couple of dial peers and transforms so send a call to a phone).

I have created a E1 crossover cable with pins 1>4 and 2>5 so I think the cable is ok as I do get the CD light on the E1 card.

on the ISDN gateway the best I have managed to achieve was a layer 2 fault then the system fell back into a state where layer 1 is down (although the unit is cabled in with the CD light), when the gateway fell back to a layer 1 issue i saw an RAI error on the router, I looked online and found a switch type mismatch could have caused this, so I have tried different switchtypes on both devices but still to no avail,

Any idea's where I maybe going wrong, I wonder have I made a big mistake in thinking that it would be possible to perform a back to back link on E1 between an ISDN gateway and a router with an e1 interface?

any and all responses much appreciated, more than happy to provide any show runs, xconfig etc...

Cheers

Think with Portals       

[Gonzalo Gasca Meza]

Hi David,

That should work fine, we setup some back to back connection long time ago using the Codian 8321 and a 2800 series.

Config should be very simple:

You are emulating ISDN then you need to define who is going to be the PSTN ( I assume will be the 2600 series)

hence you  only 2 commands extra you need to add in 2600:

clock source (internal)

network side (emulates PST switch)

You already fix the 2600 switch type.

Hope that helps.

-G

[david.sharp]

Hi Gonzalo

thanks for the response, this is the first time i have attempted to do something like this and i am a little stuck, i am now doubting as to whether or not the 2600 will support the ISDN that the gateway requires.

i now have a permenent layer 2 alarm and am stuck as to why i cannot establish layer 2 connectivity.

my line config is as follows

controller E1 1/0

clock source internal

pri-group timeslots 1-12,16

!

!

!

interface FastEthernet0/0

ip address 192.168.1.200 255.255.255.0

duplex auto

speed auto

!

interface Serial1/0:15

no ip address

no logging event link-status

isdn switch-type primary-net5

isdn protocol-emulate network

isdn incoming-voice voice

no isdn outgoing display-ie

no cdp enable

what am i missing i wonder?

Thanks for your assistance

Cheers

Dave

Think with Portals

[david.sharp]

ok i'm completely stumped now.

as far as i can see the router is setup correctly, however the isdn gateway is still saying there is a layer 2 problem.

as far as the router is concerned all is good, i wonder, any Tandberg guys out there that could shed some light onto this for me?

Cheers

Dave

Think with Portals

[Gonzalo Gasca Meza]

Just a basic check:

a) Have you tried a loopback test in 2600 E1 and Tandberg ?

b) You are using default Framing and Linecode in 2600 are the same configured in Tandberg side?

c)I noticed you are using fractional E1

pri-group timeslots 1-12,16, is Tandberg also fractional?

Have you tried full E1?

The following commands can shed some light about this problem:

debug isdn event

debug isdn event detail

debug isdn q921

show controllers e1 slot/port

http://www.cisco.com/en/US/docs/ios/12_2/dial/configuration/guide/dafchant.pdf

[david.sharp]

Hi Gonzalo

i shall have a look at performing a loop back test, according to the router the E1 ISDN setup is all good, but the Tandberg device is still showing the channels as down.

unfortunately i do not have the same control over the ISDN on the Tandberg box as i do the router, i guess what i need to do is emulate exactly what a telco would provide, this is what i thought i had done, but still no luck.

in asnwer to your questions above.

A/ i will check that.

B/ Framing is CRC4 (if i disable that i get an alarm), line code is HDB3 (as instructed in the linked document (found and followed that already))

C/ i only have a 12 port DSP, i have configured the Tandberg box as fractional also, only expecting 12 ports, what i find rather confusing is on the Tandberg box it is saying no channels are available, as if the D channel had not come up, but the router seems to think all is well. Cannot use a full E1, i did wonder if that could be what is causing the problem, maybe the D channel is sat on the wrong channel without having enough ports on the DSP maybe?

the debug commands

debug isdn events, shows nothing

debug isdn q921 shows me what is happening, but i'm not sure what is wrong here.

Daves-router#

*Mar  1 01:28:53.015: ISDN Se1/0:15 Q921: Net TX -> RRp sapi=0 tei=0 nr=0

*Mar  1 01:28:54.015: ISDN Se1/0:15 Q921: Net RX <- SABMEp sapi=0 tei=0

*Mar  1 01:28:54.015: ISDN Se1/0:15 Q921: Net TX -> RRp sapi=0 tei=0 nr=0

*Mar  1 01:28:54.019: ISDN Se1/0:15 Q921: Net TX -> UAf sapi=0 tei=0

*Mar  1 01:28:55.015: ISDN Se1/0:15 Q921: Net RX <- SABMEp sapi=0 tei=0

*Mar  1 01:28:55.019: ISDN Se1/0:15 Q921: Net TX -> UAf sapi=0 tei=0u all

All possible debugging has been turned off

and the show controller command returns

E1 1/0 is up.

  Applique type is Channelized E1 - balanced

  Far End Block Errors Detected

  No alarms detected.

  alarm-trigger is not set

  Version info Firmware: 20090113, FPGA: 20, spm_count = 0

  Framing is CRC4, Line Code is HDB3, Clock Source is Internal.

  CRC Threshold is 320. Reported from firmware  is 320.

  Data in current interval (592 seconds elapsed):

     3 Line Code Violations, 4 Path Code Violations

     0 Slip Secs, 0 Fr Loss Secs, 2 Line Err Secs, 0 Degraded Mins

     2 Errored Secs, 1 Bursty Err Secs, 0 Severely Err Secs, 1 Unavail Secs

and the show ISDN status

Global ISDN Switchtype = primary-net5

ISDN Serial1/0:15 interface

        ******* Network side configuration *******

        dsl 0, interface ISDN Switchtype = primary-net5

    Layer 1 Status:

        ACTIVE

    Layer 2 Status:

        TEI = 0, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

    Layer 3 Status:

        0 Active Layer 3 Call(s)

    Active dsl 0 CCBs = 0

    The Free Channel Mask:  0x80000FFF

    Number of L2 Discards = 0, L2 Session ID = 175

    Total Allocated ISDN CCBs = 0

i wasn't expecting getting the line up to be the hard part in all honesty.

again thank you very much for your pointers much appreciated

Cheers

Dave

Think with Portals

[david.sharp]

Yep it works with software loopback.

Think with Portals

[david.sharp]

Hi Gonzalo

It works!!!! however i have an embarrassing mistake to admit to.

firstly thanks for your pointers, the network site emulation was vital, i might have missed that otherwise.

the reason it didn't, or wasn't working is.

"i made a mistake when creating the crossover cable".

i did pins 1 to 4 and 2 to 5 but only in one direction, i neglected to do pints 4 to 1 and 5 to 2 in the opposing direction.

i have re-made the cable with the correct pinout and buzzed the pins to ensure a completed circuit and the moment iplugged it in i got a green light 

what an embarassing mistake to make, but again thank you very much for your pointers and assistance.

So for any one else who may make the same newbie mistake, link to additional topic below

https://supportforums.cisco.com/thread/192658

Cheers

dave

Think with Portals