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E1 cards for PBX to PSTN connectivity

Hi guys,

I have a PBX with an E1 link going to R1. R1 goes via ethernet to R2 which has an E1 going to the UK PSTN. (I haven't actually installed the routers yet).

The questions:

1. What kind of E1 cards to I require? I've seen both balanced and unbalanced versions of NM-1CE1T1-PRI and NM-1CE1.

2. What config is required to activate the E1 cards?

3. What E1/voice specific config is required to carry calls from the PBX to the PSTN?

4. How does R2 know to use the different E1 channels? Is it by using multiple dial-peers?



Re: E1 cards for PBX to PSTN connectivity

See there is nothing, it very simple.

E1 will connect to your router...

configure following configurations

controller E1 0/3 (Slot you should know, where you are puting E1 MFT card)

framing NO-CRC4

channel-group 0 timeslots 1-31

Automatically one seriall interface pop up.

interface Serial0/3:0

description ### XXXXX XXXX XXXXX ###

bandwidth 2048

no ip address (You can put IP address, if not using multilink)

encapsulation ppp

no ip route-cache

load-interval 60

ppp multilink

multilink-group 1 (You can bind more than one link into Multilink and get aggregate bandwidth)

interface Multilink1

description ##### MultiLink #####

ip address {IP Add} {Subnet Mask}

load-interval 30

ppp multilink

multilink-group 1 (Should be match with Interface multilink no.)

( If you are not configuring more than one link .. Please ignore Multilink configuration and multilink command into serial interface.)

Now, router's ehthernet interface will terminate into PBX..

Now PBX GUY know to distribute Number expantion.

If any queries please revert.


1) MFT voice card required. VWIC2-2MFT-T1/E1

More information and question answer you can get from following link:

2) Configuration already given you.

3) There is no any specific requirement for voice setup.

One another solution.... But thi is more flexible into call center setup.

You can connect router Fastethernet interface to 4510 Series switch and connect IP phones with the switch. With that IP phone, you can connect PC also.

You have to create two different VLAN, one for Voice and another for Data.

So, call center agent can use VOICE as well as Data from Signle.... Switch port.


If any queries please revert.


Dharmesh Purohit


Dharmesh Purohit

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