Feb 10, 2014 - Asterisk    No Comments

A fix for new Asterisk MOH file not found issue

The new Asterisk PBX system for some odd reason have an issue with MOH not working by default. Digging deeper I found out that there’s a mismatch in directory names where asterisk looks for these files.

It looks like the GUI portion of asterisk uploads files to /var/lib/asterisk/mohmp3 but config files set to look in /var/lib/asterisk/moh. the easiest fix is as below.

mv /var/lib/asterisk/mohmp3/*.* /var/lib/asterisk/moh/
rm -f /var/lib/asterisk/mohmp3
ln -s /var/lib/asterisk/moh /var/lib/asterisk/mohmp3

This will move all content on mohmp3 directory to moh, delete mohmp3 folder and then create a symlink named mohmp3 targeting moh. Now you don’t have to mess about with editing any config files.

Feb 10, 2014 - Cisco, VoIP    No Comments

A sample QoS config for VOIP service on a Cisco router

The config below is a sample for configuring QoS on a Cisco router. The below config is good for 10 simultaneous calls on G.711 codec. This QoS setting is geared towards SHDSL/EoC/Fibre services with guaranteed bandwidth.

!
class-map match-any VoIP
match protocol h323
match protocol rtcp
match protocol rtp
match protocol sip
!
policy-map VOIPQoS
class VoIP
priority 2000
set dscp ef
class class-default
fair-queue
!
interface GigabitEthernet0/0
service-policy output VOIPQoS
!

Feb 6, 2014 - Cisco    No Comments

Setting up NTP, Timezone and DST setting on a Cisco rotuer

Simply use the following example to setup the router to get date time from a NTP server and show the current time according to the timezone and DST settings.

The below example configures a NTP server, then sets the time zone for GMT+10 and sets the DST time frames.

Router(config)#ntp server x.x.x.x
Router(config)#clock timezone AEST 10 0
Router(config)#clock summer-time AEDT recurring 1 Sun Oct 2:00 1 Sun Apr 3:00

Feb 6, 2014 - Asterisk, Cisco, VoIP    No Comments

Setting up a Cisco router for auto-provisioning of Cisco handsets

Here is a sample config to setup auto-provisioning for Cisco handsets. This only covers the part of distributing the config files to the handsets and not the config file creation part.

This assumes that VLAN100 is the VOICE VLAN and PCs are connecting via the PC port at the back of the phones.

!
ip dhcp pool VOICE
network 192.168.100.0 255.255.255.0
default-router 192.168.100.1
dns-server 192.168.100.1
option 66 ascii "http://auto.provisioning.url/"
lease infinite
!
interface Vlan100
description VoiceVLAN
ip address 192.168.100.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
interface FastEthernet3
description ToVoiceSwitch
switchport mode trunk
switchport voice vlan 100
!

Feb 6, 2014 - Cisco    No Comments

Disabling inter-VLAN routing using ACLs

While working on a customer’s router config he requested the following to be done.

  • 3 LAN subnets
  • IP’s must assigned by DHCP.
  • All 3 subnets must have access to internet.
  • Devices on each LAN should not be able to communicate with each other.

As the customer had a Cisco 881 the easiest way this could be achieved is with VLANs.  Here’s how I did it.

inter-vlan

!
ip dhcp pool LAN
network 192.168.1.0 255.255.255.0
dns-server 220.233.0.3 58.96.1.28 8.8.8.8
default-router 192.168.1.1
!
ip dhcp pool LAN2
network 192.168.2.0 255.255.255.0
dns-server 220.233.0.3 58.96.1.28 8.8.8.8
default-router 192.168.2.1
!
ip dhcp pool LAN3
network 192.168.3.0 255.255.255.0
dns-server 220.233.0.3 58.96.1.28 8.8.8.8
default-router 192.168.3.1
!
interface FastEthernet0
no ip address
!
interface FastEthernet1
switchport access vlan 2
no ip address
!
interface FastEthernet2
switchport access vlan 3
no ip address
!
interface FastEthernet3
no ip address
shutdown
!
interface FastEthernet4
ip address 58.96.0.0 255.255.255.254
ip nat outside
ip virtual-reassembly in
rate-limit output 9800000 1250000 2500000 conform-action transmit exceed-action drop
duplex full
speed 100
!
interface Vlan1
ip address 192.168.1.1 255.255.255.0
ip access-group 101 in
ip nat inside
ip virtual-reassembly in
!
interface Vlan2
description LAN2
ip address 192.168.2.1 255.255.255.0
ip access-group 102 in
ip nat inside
ip virtual-reassembly in
!
interface Vlan3
description LAN3
ip address 192.168.3.1 255.255.255.0
ip access-group 103 in
ip nat inside
ip virtual-reassembly in
!
ip nat inside source list 1 interface FastEthernet4 overload
!
access-list 1 permit 192.168.0.0 0.0.3.255
access-list 1 permit any
access-list 101 deny ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255
access-list 101 deny ip 192.168.1.0 0.0.0.255 192.168.3.0 0.0.0.255
access-list 101 permit ip any any
access-list 102 deny ip 192.168.2.0 0.0.0.255 192.168.1.0 0.0.0.255
access-list 102 deny ip 192.168.2.0 0.0.0.255 192.168.3.0 0.0.0.255
access-list 102 permit ip any any
access-list 103 deny ip 192.168.3.0 0.0.0.255 192.168.1.0 0.0.0.255
access-list 103 deny ip 192.168.3.0 0.0.0.255 192.168.2.0 0.0.0.255
access-list 103 permit ip any any
!