Scott Donnelly

Asterisk to Voiceflex - an example on the NSLU2

Published on
Last updated on

I have had numerous comments and requests regarding Asterisk configuration for Voiceflex. I have neglected my blog somewhat lately, but when I googled for “BCM50 SIP” the other day, I was suprised to see my own blog high up the listings! I have decided to revisit this, as it has obviously generated a lot of interest.

I have a bash script that I used on the Linksys NSLU2 (“the SLUG”) in order to quickly configure Asterisk to act as a gateway between a Nortel BCM50 and Voiceflex’s SIP trunks. Although there is no longer a need to use the NSLU2 in this fashion, as Voiceflex can dispense with SIP authentication when the BCM50 is on a static IP, I will post the scripts, as well as the relevant Asterisk config files, as they may be useful for anybody that wants to configure Asterisk with SIP trunks.

Firstly, the Asterisk configs: obviously, do not use these as-is, you will need to change the details to suit!

sip.conf

[general]

context=default
bindport=5060
bindaddr=0.0.0.0
srvlookup=yes
domain=asterisk

disallow=all
allow=alaw,g729,g723
language=en
relaxdtmf=yes
trustrpid=no
useragent=Asterisk PBX
promiscredir=yes
canreinvite=yes

domain=146.101.248.200,incoming-voiceflex
domain=192.168.40.6,incoming-voiceflex
domain=10.10.10.10,incoming-bcm
domain=10.10.11.11,default

#include /etc/asterisk/sip_nat.conf

#include /etc/asterisk/sip_accounts.conf

[sip-bcm]
type=peer
host=10.10.10.10
context=incoming-bcm

#include /etc/asterisk/sip_og_context.conf

; sip ext for xlite, for testing
[200]
type=friend
regexten=200
secret=donttell
context=default
host=10.10.10.10
canreinvite=no
insecure=port,invite
sip_nat.conf 
externip=11.11.11.11
localnet=192.168.192.0/24
nat=yes
sip_accounts.conf 
;sip_accounts.conf generated by autoasterflex
register => 12345678:shhhsecret@sip.voiceflex.com

registertimeout=20
registerattempts=0

[authentication]
auth=12345678:shhhsecret@146.101.248.200
auth=12345678:shhhsecret@voiceflex
auth=12345678:shhhsecret@sip.voiceflex.com
sip_og_context.conf 
[voiceflex]
type=friend
callerid=01234567890
fromuser=01234567890
defaultuser=12345678@voiceflex
disallow=all
allow=alaw,ulaw,g729
fromdomain=voiceflex
secret=shhhsecret
host=sip.voiceflex.com
insecure=invite,port
context=incoming-voiceflex
extensions_incoming_voiceflex.conf 
[incoming-voiceflex]
exten => s,1,Dial(SIP/666666@sip-bcm,,r);
exten => 666666,1,Dial(SIP/666666@sip-bcm,,r);
extensions.conf 
; extensions.conf - asterisk dialplan

[general]
static=yes
writeprotect=no
autofallthrough=yes
clearglobalvars=no
priorityjumping=no

[globals]

[incoming-bcm]
exten => 200,1,Dial(SIP/200,,r);
exten => _9.,1,Dial(SIP/${EXTEN:1}@voiceflex,,r);
exten => _8.,1,SIPDtmfMode(inband);
exten => _8.,2,Dial(SIP/${EXTEN:1}@voiceflex,,r);

;this context must be absent prior to  running autoasterflex
;[incoming-voiceflex]
;exten => s,1,Dial(SIP/234567@sip-bcm,,r);
;exten => 234567,1,Dial(SIP/234567@sip-bcm,,r);

[default]
exten => _9.,1,Dial(SIP/${EXTEN:1}@voiceflex,,r);
exten => 300,1,Dial(SIP/234567@sip-bcm,,r);
exten => 234567,1,Dial(SIP/234567@sip-bcm,,r);

#include /etc/asterisk/extensions_incoming_voiceflex.conf
Finally, here is a little shell script that I was using, in order to configure an NSLU2 with Asterisk already installed, to configure the SIP trunks. USE WITH CAUTION - answering "y" to "Change IP & DNS settings (y/n) ?" will re-write the network interface config (/etc/network/interfaces) and DNS client config (/etc/resolf.conf) on the machine that you run it on (if it is Linux based.) I would advise anybody using the script to exercise care doing this, and only to do so if you have read and understand the script. autoasterflex.sh 
#!/bin/bash

#autoasterflex

echo "Caller ID of incoming SIP Trunk?"
read CALLERID
echo "SIP Account number?"
read SIPACCT
echo "SIP Account password?"
read SIPPASS
echo "PBX IP Address?"
read BCMIP
echo "WAN IP Address?"
read EXTERNIP
echo "Local network? (eg 192.168.0.1/24)"
read LOCALNET
echo "Digits to send to pbx as received digits?"
read DDI
echo "Change IP & DNS settings (y/n) ?"
read CHANGEIP

if [ "$CHANGEIP" == "y" ]; then
    echo "Slug IP?"
    read SLUGIP
    echo "Slug Netmask?"
    read SLUGSN
    echo "Slug Default Gateway?"
    read SLUGDGW
    echo "DNS Server?"
    read SLUGDNS
fi

# modify existing sip_og_context.conf
sed -i "s/callerid=.*/callerid=${CALLERID}/" /etc/asterisk/sip_og_context.conf
sed -i "s/fromuser=.*/fromuser=${CALLERID}/" /etc/asterisk/sip_og_context.conf
sed -i "s/defaultuser=.*/defaultuser=${SIPACCT}@voiceflex/" /etc/asterisk/sip_og_context.conf
sed -i "s/secret=.*/secret=${SIPPASS}/" /etc/asterisk/sip_og_context.conf

# delete existing si_accounts.conf, create a new one
rm -f /etc/asterisk/sip_accounts.conf
echo ";sip_accounts.conf generated by autoasterflex" >> /etc/asterisk/sip_accounts.conf
echo "register => ${SIPACCT}:${SIPPASS}@sip.voiceflex.com" >> /etc/asterisk/sip_accounts.conf
echo "" >> /etc/asterisk/sip_accounts.conf
echo "registertimeout=20" >> /etc/asterisk/sip_accounts.conf
echo "registerattempts=0" >> /etc/asterisk/sip_accounts.conf
echo "" >> /etc/asterisk/sip_accounts.conf
echo "[authentication]" >> /etc/asterisk/sip_accounts.conf
echo "auth=${SIPACCT}:${SIPPASS}@146.101.248.200" >> /etc/asterisk/sip_accounts.conf
echo "auth=${SIPACCT}:${SIPPASS}@voiceflex" >> /etc/asterisk/sip_accounts.conf
echo "auth=${SIPACCT}:${SIPPASS}@sip.voiceflex.com" >> /etc/asterisk/sip_accounts.conf

#delete existing sip_nat.conf,  create a new one
rm -f /etc/asterisk/sip_nat.conf
echo "externip=${EXTERNIP}" >> /etc/asterisk/sip_nat.conf
echo "localnet=${LOCALNET}" >> /etc/asterisk/sip_nat.conf
echo "nat=yes" >> /etc/asterisk/sip_nat.conf

#check extensions.conf has #include /etc/asterisk/extensions_incoming_voiceflex.conf, append if absent
INCVFLEXCONFPRESENT=`grep '/etc/asterisk/extensions_incoming_voiceflex.conf' /etc/asterisk/extensions.conf`
if [ "" == "$INCVFLEXCONFPRESENT" ]; then
    echo ""  >> /etc/asterisk/extensions.conf
    echo "#include /etc/asterisk/extensions_incoming_voiceflex.conf" >> /etc/asterisk/extensions.conf
fi

#delete existing extensions_incoming_voiceflex.conf, recreate
rm -f /etc/asterisk/extensions_incoming_voiceflex.conf
echo "[incoming-voiceflex]" >> /etc/asterisk/extensions_incoming_voiceflex.conf
echo "exten => s,1,Dial(SIP/${DDI}@sip-bcm,,r);" >> /etc/asterisk/extensions_incoming_voiceflex.conf
echo "exten => ${DDI},1,Dial(SIP/${DDI}@sip-bcm,,r);" >> /etc/asterisk/extensions_incoming_voiceflex.conf

# modify sip.conf
sed -i "s/domain=.*,incoming-bcm/domain=${BCMIP},incoming-bcm/" /etc/asterisk/sip.conf
sed -i "s/host=.*/host=${BCMIP}/" /etc/asterisk/sip.conf

if [ "$CHANGEIP" == "y" ]; then
    #recreate /etc/network/interfaces
    rm -f /etc/network/interfaces
    echo "# /etc/network/interfaces" >> /etc/network/interfaces
    echo "# recreated by autoasterflex" >> /etc/network/interfaces
    echo "#" >> /etc/network/interfaces
    echo "# the loopback interface" >> /etc/network/interfaces
    echo "auto lo" >> /etc/network/interfaces
    echo "iface lo inet loopback" >> /etc/network/interfaces
    echo "#" >> /etc/network/interfaces
    echo "# the interface used by default during boot" >> /etc/network/interfaces
    echo "auto eth0" >> /etc/network/interfaces
    echo "#" >> /etc/network/interfaces
    echo "# static entry for eth0" >> /etc/network/interfaces
    echo "iface eth0 inet static" >> /etc/network/interfaces
    echo "    address ${SLUGIP}" >> /etc/network/interfaces
    echo "    netmask ${SLUGSN}" >> /etc/network/interfaces
    echo "    gateway ${SLUGDGW}" >> /etc/network/interfaces

    #recreate /etc/resolf.conf
    rm -f /etc/resolv.conf
    echo "search workgroup" >> /etc/resolf.conf
    echo "nameserver ${SLUGDNS}" >> /etc/resolv.conf
fi

#done
echo "Changes done. execute shutdown -r now to restart with new settings."

I hope this helps.