Interconnecting Asterisk SS7 with Ericsson™ AXE® Switch

History and Propose of the solution

SS7 is suit of protocols and the language between telecom switches. since VOIP is new, still many telecom networks require SS7 for interconnection. There are different solutions and hardware available for interconnection between VOIP and SS7 networks. In this document I will propose a simple way of interconnection if your telecom counterpart is running AXE switch and you are looking for a reliable and cheap and fast interconnection solution.

For 4 E1 link Capacity:

First of all it is suggested to buy E1 hardware in order to physically connect to AXE Switches.
There are variety products from cheap Chinese, to expensive with hardware echo-cancellation based hardware are available, for this interconnection I used Sangoma™ hardware which has a good reputation and fairly stable with echo cancellation.

For this project I used:

• Asterisk 1.8.22.0
• Dahdi 2.6.2
• Chan_SS7 7.2.2
• Sangome Wanpipe 7.0.5 ( only if you are using Sangoma Hardware)

Installation

1. Install the Sangoma or any E1 Hardware to your linux box
2. Install Dahdi, if you don’t know how, consult the following link:
   • https://wiki.asterisk.org/wiki/display/AST/Building+and+Installing+DAHDI
3. Install Sangoma wanpipe which the installation instruction is available from the below link:
   • http://wiki.sangoma.com/wanpipe-linux-asterisk-install
4. Install Free version of Chan_SS7:
   • http://www.netfors.com/chan_ss7_free
5. Install Asterisk:
   • Asterisk Step-by-step Installation

Testing and Configuration:

If you are using sangoma it is needed to start the wanrouter engine by

  #wanrouter start

If everything is fine you will receive the following messages like:

Configuring interfaces: w1g1
done.
Configuring interfaces: w2g1
done.
Configuring interfaces: w3g1
done.
Configuring interfaces: w4g1
done.

Then it is time to configure the dahdi; so we need to modify the /etc/dahdi/system.conf file:
In this example I used channel 1 and 32 for signaling (mtp2=1 mtp2=32)

####################################################
loadzone=fr
defaultzone=fr

#Sangoma A104 port 1 [slot:4 bus:3 span:1] <wanpipe1>
span=1,1,0,ccs,hdb3
bchan=2-31
mtp2=1

#Sangoma A104 port 2 [slot:4 bus:3 span:2] <wanpipe2>
span=2,2,0,ccs,hdb3
bchan=33-62
mtp2=32

#Sangoma A104 port 3 [slot:4 bus:3 span:3] <wanpipe3>
span=3,3,0,ccs,hdb3
bchan=63-93

#Sangoma A104 port 4 [slot:4 bus:3 span:4] <wanpipe4>
span=4,4,0,ccs,hdb3
bchan=94-124
####################################################

When the modification is done

 #dahdi_cfg –v
 #dahdi_tool

Wait until alarms become OK

edit /etc/asterisk/ss7.conf

####################################################
[linkset-siuc]; <--the name of Linkset which is siuc
enabled => yes 
enable_st => no 
use_connect => yes  ; <-- Reply incoming call with CON rather than ACM and ANM
hunting_policy => even_mru
context => ss7-in; <-- this is refered the context in /etc/asterisk/extentions. ...