CIPTV2 – Lab Update Part 2 – How to setup a home lab with ISDN

All,

So my CIPTV2 lab is coming along nicely… Just a reminder here is the topology I am working with:

CIPTV2 Lab Topology

Everything was fairly straight forward until I got to the PSTN requirement..

Physicals/Kit

My PSTN Router is a Cisco 2821 with the following WIC cards installed to provide T1/E1 connections:

WIC Slot 0: VWIC-1MFT-E1=

WIC Slot 2: VWIC-2MFT-T1-DI=

WIC Slot 3: VWIC-1MFT-G703=

HQ, BR1 and BR2 all have either a T1/E1 connection back to the PSTN router.

Each cable is a T1/E1 crossover cable. Details on how to make this cable are here:
https://supportforums.cisco.com/discussion/11978121/voicedata-t1e1-crossover-back-back-cable-diy-or-buy

So that is the physicals with the PSTN router acting as an ISDN hub and HQ, BR1 and BR2 all acting as spokes.

Configuration for ISDN

PSTN Router – E1

Global Configuration

network-clock-participate wic 0
isdn switch-type primary-net5

E1

controller E1 0/2/0
clock source internal (Because its PSTN side, it is the clock provider)
pri-group timeslots 1-31 (CCS – Article I wrote around this – https://ccieme.wordpress.com/2015/01/08/voice-gateways-understanding-digital-voice-ports/)

Signaling

interface Serial0/2/0:15 (D Channel)
no ip address
encapsulation hdlc
isdn switch-type primary-net5
isdn timer T310 120000
isdn protocol-emulate network (Key command!!)
isdn incoming-voice voice
no cdp enable

Spoke Router – E1

Global Configuration

network-clock-participate wic 0
isdn switch-type primary-net5

E1

controller E1 0/1/1
pri-group timeslots 1-31 (Again CCS with dedicated signaling channel)

Signaling

interface Serial0/1/1:15
no ip address
encapsulation hdlc
isdn switch-type primary-net5
isdn incoming-voice voice
no cdp

This should be enough to give you your ISDN connectivity! If all is good you should see this on each T1 or E1:

PSTN_WAN#sh isdn status
Global ISDN Switchtype = primary-net5
ISDN Serial0/0/0:15 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 (This is the bit you want to see! Anything else is bad and you will need to check your config)
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0xFFFF7FFF
Number of L2 Discards = 0, L2 Session ID = 0

Now all you need is your dialpeers! 😉