Categories
Cards

Digium Cards

digium_cards

Not only was Digium the first vendor of telephony interface cards built specifically for Asterisk, but it has always been the market leader, with over 50% of the world’s board business.

Analogue Cards

Digium analogue telephony cards are high-performance, highly reliable and cost-effective interfaces for POTS lines to your Asterisk solution. Multiple applications can be created to satisfy the business needs of any organization when using Digium analogue cards in concert with Asterisk software, the Linux® operating system and standard PC/server platforms.

Digital Cards

Digium’s super-reliable digital line cards connect Asterisk-based communication systems to T1, E1, J1 and ISDN-BRI interfaces.

Hybrid Cards

The Digium Hx8 Series are high-performance, cost-effective hybrid analogue and BRI telephony interface cards providing the capability to seamlessly integrate mixed-mode environments in a single device. Use the telephony card selector to identify the card that fits your requirements.

  • RoHS compliant
  • Manufactured in an ISO 9001:2001 certified facility in the United States
  • Maintain an MTBF greater than one (1) million hours
  • 5-year hardware warranty

 

For configuration and pricing please email or call us. We always want to speak to customers buying cards to make sure that it will be compatible with their server hardware.

Categories
Case Studies

Multi-Site Multi-Country Asterisk network

UPDATE

We have recently added the 5th system to the customers international VoIP network. This system was for their Polish office and is linked to their Tokyo, Sydney, Singapore and London office systems.

Globe

For this site a Sangoma FREEPBX 60 system was chosen for ease of remote deployment and reliability.    The Tokyo & Sydney offices already has a Xorcom XR2000 systems whilst the London and Singapore offices have a Openvox  Asterisk solutions.  .

xe2000-xe3000

For the New International offices FreePBX systems were chosen as they provide a full turnkey system that can be sent out to the office plugged in. The systems initially obtain their IP address by DHCP and once a port is forwarded through the firewall to this address a fixed IP address is assigned and the customer firewall updated. Access to The GUI is by a SSH tunnel so that other than a random port for SSH and a port for IAX2 no other ports need to be opened on the customer firewall. Endpoint manager makes the deployment of handsets on the remote systems a simple and reliable process.

All systems have been linked by IAX2 trunks and the dial-plan configured so that desk to desk calls can be made between all offices and outgoing calls break out of the closest geographic system, for example a user in Sydney making a call to a UK number will have the call originate from the London system and the same goes for Tokyo, Singapore and Polish users calling UK or international numbers.

The network of systems is key to the support of the customers 24×7 support service. This is controlled by a dial-plan that is complicated by the fact that Japan does not have “Daylight saving” so even though the calls land on the UK system we had to configure the dial-plan to take into account local time in Tokyo and not base routing solely on UK time.  This has proved reliable and very successful.

All systems on the network are monitored 24×7 by our Nagios monitoring platform, Not only monitoring Asterisk but also monitoring the status of the international IAX2 trunks.

 

Categories
Blog

A new patent troll.

SIP Trunking

In the last few weeks a large sleeping troll has come out of hibernation and seems set on disrupting the whole voip market.

Quote

“BT is engaged in licensing an extensive range of standards related patents that address the key features of SIP Trunking providers and VOIP operators providers.

BT’s Patents address a wide range of fundamental capabilities now in widespread deployment, such as:

  • Setting up a call
  • Breaking out to other networks
  • Managing resources efficiently
  • Registering terminal to a network
  • Cost effective call completion
  • Monitoring and alerting of IP call quality”

Well that pretty much covers all of the workings of a SIP network. A full list of the patents is here  .

But its not Just BT, AT&T also have claims over SIP as well see here for a list.

It seems that some of the major patent holders see more money in the licencing of the now ubiquitous SIP protocol than maybe supplying it to customer. Which is a shame as the only ones who will make any money will be the Lawyers in the end.

More to follow on this I’m sure….

Categories
Blog

Zen like pondering about telephony and Asterisk

Categories
Knowledge Base

Installing Asterisk 11 on Centos 6.3

asteriskThis is a short video tutorial on the installation of Asterisk 11, I have included the blog and video in one place for ease of viewing

First, you will want to be sure that your server OS is up to date.

yum update -y

Disable SELinux by changing “enforcing” to “disabled” in /etc/selinux/config. Use a text editor or copy and paste this command.

sed -i s/SELINUX=enforcing/SELINUX=disabled/g /etc/selinux/config

After you update and disable SELinux, you’ll need to reboot.

reboot

Next, you will want to resolve basic dependencies. (More information on Asterisk dependencies.)

yum install -y make wget openssl-devel ncurses-devel  newt-devel libxml2-devel kernel-devel gcc gcc-c++ sqlite-devel

Change into the /usr/src/ directory to store your source code.

cd /usr/src/

Download the source tarballs. These commands will get the current release of DAHDI 2.6, libpri 1.4 and Asterisk 11.

wget http://downloads.asterisk.org/pub/telephony/dahdi-linux-complete/dahdi-linux-complete-current.tar.gz
wget http://downloads.asterisk.org/pub/telephony/libpri/libpri-1.4-current.tar.gz
wget http://downloads.asterisk.org/pub/telephony/asterisk/asterisk-11-current.tar.gz

Extract the files from the tarballs.

tar zxvf dahdi-linux-complete*
tar zxvf libpri*
tar zxvf asterisk*

For the next set of commands it is important to follow the proper order: DAHDI first, then libpri, then Asterisk.

Install DAHDI.

cd /usr/src/dahdi-linux-complete*
make && make install && make config

Install libpri.

cd /usr/src/libpri*
make && make install

Change to the Asterisk directory.

cd /usr/src/asterisk*

In the next step, running the “configure” script will vary depending on whether your system is 32-bit or 64-bit. (Watch the video for more details.) When the menuselect command runs, select your options, then choose “Save and Exit” and the install will continue.

Use this command if you are installing Asterisk on 32bit CentOS.

./configure && make menuselect && make && make install

Use this command if you are installing Asterisk on 64bit CentOS.

./configure --libdir=/usr/lib64 && make menuselect && make && make install

Optional: If you ran into errors you will want to clean the install directory before recompiling.

make clean && make distclean

Once you have an error-free install, copy the sample files from the configs subdirectory into /etc/asterisk.

make samples

Then add the Asterisk start script to the /etc/init.d/ directory

make config

Start DAHDI.

service dahdi start

Start Asterisk.

service asterisk start

Connect to the Asterisk CLI.

asterisk -rvvv

And now you have Asterisk 11 running on CentOS 6!

Original Article written by Billy Chia @ digium

Categories
Handsets

Digium Handsets

The Only Phones Built Specifically For Asterisk

  • asteriskEasy provisioning from Asterisk or AsteriskNOW
  • Integrated with Asterisk voicemail, directory, parking, call recordings, call queues and more
  • Build custom phone apps with a simple JavaScript API

Digium’s family of IP Phones are the first on the market built specifically for use with Asterisk and Asterisk-based systems. All models include HD audio and plug-and-play deployment at a price that fits any budget. With multiple line appearances, context-aware soft keys, and advanced applications that integrate directly with Asterisk features, the Digium phones offer a better user experience than any other phone on the market.

Asterisk Phone Features

Smart Software

Access to information is the key to productivity in today’s business environment. The integrated applications that come standard with all Digium phones put critical information at your fingertips. With voicemail, call log, contacts, phone status, user presence, parking, call recording and call queue interface, the Digium phones provide simple, intuitive access to a wealth of information, saving valuable time.

 Simplified Provisioning

Standards-based IP phones have a reputation for being difficult to install and configure. Most systems require changes to network configurations or additional components to facilitate deployment. Digium phones support plug-and-play provisioning. Simply plug in the phone and it will automatically discover Asterisk systems on the network. Select the user you want to assign to the phone and the proper configuration is instantly loaded. For larger deployments you can pre-assign phones by tying a MAC address to an Asterisk user. It’s that simple.

Custom Applications

Most desktop phones come with a fixed feature-set that is determined exclusively by the manufacturer. Digium phones are different. All models include the Digium app engine, an innovative feature that makes it remarkably simple to build and deploy custom apps. All of the productivity apps that ship with a Digium Phone are written with the JavaScript API that is used by the app engine. A BETA version of the phone firmware with app development tools is available at phones.digium.com, along with documentation for developing your custom apps.

Getting Started With Digium Phones

Get AsteriskDigium phones will work with any version of Asterisk. However, we’ve added some compelling features that are only available today in Asterisk 11 or in special branches of Asterisk 1.8 (seeCertified Asterisk) and Asterisk 10 (the -digiumphones branch). To take advantage of simple provisioning, integrated applications and the app engine, you will need to use one of these versions

Call or email for sales enquiries 

Categories
Elastix Support Knowledge Base

Setting up extensions in Elastix

Elastix Asterisk IPPXThis is a short video on the setting up of extensions on the Elastix Asterisk based IPPX.

 

Categories
Knowledge Base

VoIP – Per Call Bandwidth

These protocol header assumptions are used for the calculations:

  • 40 bytes for IP (20 bytes) / User Datagram Protocol (UDP) (8 bytes) / Real-Time Transport Protocol (RTP) (12 bytes) headers.
  • Compressed Real-Time Protocol (cRTP) reduces the IP/UDP/RTP headers to 2or 4bytes (cRTP is not available over Ethernet).
  • 6 bytes for Multilink Point-to-Point Protocol (MP) or Frame Relay Forum (FRF).12 Layer 2 (L2) header.
  • 1 byte for the end-of-frame flag on MP and Frame Relay frames.
  • 18 bytes for Ethernet L2 headers, including 4 bytes of Frame Check Sequence (FCS) or Cyclic Redundancy Check (CRC).

Note: This table only contains calculations for the default voice payload

Codec Information Bandwidth Calculations
Codec & Bit Rate (Kbps) Codec Sample Size (Bytes) Codec Sample Interval (ms) Mean Opinion Score (MOS) Voice Payload Size (Bytes) Voice Payload Size (ms) Packets Per Second (PPS) Bandwidth MP or FRF.12 (Kbps) Bandwidth w/cRTP MP or FRF.12 (Kbps) Bandwidth Ethernet (Kbps)
G.711 (64 Kbps) 80 Bytes 10 ms 4.1 160 Bytes 20 ms 50 82.8 Kbps 67.6 Kbps 87.2 Kbps
G.729 (8 Kbps) 10 Bytes 10 ms 3.92 20 Bytes 20 ms 50 26.8 Kbps 11.6 Kbps 31.2 Kbps
G.723.1 (6.3 Kbps) 24 Bytes 30 ms 3.9 24 Bytes 30 ms 33.3 18.9 Kbps 8.8 Kbps 21.9 Kbps
G.723.1 (5.3 Kbps) 20 Bytes 30 ms 3.8 20 Bytes 30 ms 33.3 17.9 Kbps 7.7 Kbps 20.8 Kbps
G.726 (32 Kbps) 20 Bytes 5 ms 3.85 80 Bytes 20 ms 50 50.8 Kbps 35.6 Kbps 55.2 Kbps
G.726 (24 Kbps) 15 Bytes 5 ms 60 Bytes 20 ms 50 42.8 Kbps 27.6 Kbps 47.2 Kbps
G.728 (16 Kbps) 10 Bytes 5 ms 3.61 60 Bytes 30 ms 33.3 28.5 Kbps 18.4 Kbps 31.5 Kbps
G722_64k(64 Kbps) 80 Bytes 10 ms 4.13 160 Bytes 20 ms 50 82.8 Kbps 67.6Kbps 87.2 Kbps
ilbc_mode_20(15.2Kbps) 38 Bytes 20 ms NA 38 Bytes 20 ms 50 34.0Kbps 18.8 Kbps 38.4Kbps
ilbc_mode_30(13.33Kbps) 50 Bytes 30 ms NA 50 Bytes 30 ms 33.3 25.867 Kbps 15.73Kbps 28.8 Kbps

Explanation of Terms

Codec Bit Rate (Kbps) Based on the codec, this is the number of bits per second that need to be transmitted to deliver a voice call. (codec bit rate = codec sample size / codec sample interval).
Codec Sample Size (Bytes) Based on the codec, this is the number of bytes captured by the Digital Signal Processor (DSP) at each codec sample interval. For example, the G.729 coder operates on sample intervals of 10 ms, corresponding to 10 bytes (80 bits) per sample at a bit rate of 8 Kbps. (codec bit rate = codec sample size / codec sample interval).
Codec Sample Interval (ms) This is the sample interval at which the codec operates. For example, the G.729 coder operates on sample intervals of 10 ms, corresponding to 10 bytes (80 bits) per sample at a bit rate of 8 Kbps. (codec bit rate = codec sample size / codec sample interval).
MOS MOS is a system of grading the voice quality of telephone connections. With MOS, a wide range of listeners judge the quality of a voice sample on a scale of one (bad) to five (excellent). The scores are averaged to provide the MOS for the codec.
Voice Payload Size (Bytes) The voice payload size represents the number of bytes (or bits) that are filled into a packet. The voice payload size must be a multiple of the codec sample size. For example, G.729 packets can use 10, 20, 30, 40, 50, or 60 bytes of voice payload size.
Voice Payload Size (ms) The voice payload size can also be represented in terms of the codec samples. For example, a G.729 voice payload size of 20 ms (two 10 ms codec samples) represents a voice payload of 20 bytes [ (20 bytes * 8) / (20 ms) = 8 Kbps ]
PPS PPS represents the number of packets that need to be transmitted every second in order to deliver the codec bit rate. For example, for a G.729 call with voice payload size per packet of 20 bytes (160 bits), 50 packets need to be transmitted every second [50 pps = (8 Kbps) / (160 bits per packet) ]

 

Bandwidth Calculation Formulas

These calculations are used:

  • Total packet size = (L2 header: MP or FRF.12 or Ethernet) + (IP/UDP/RTP header) + (voice payload size)
  • PPS = (codec bit rate) / (voice payload size)
  • Bandwidth = total packet size * PPS
Categories
Blog

Yealink T20P the new entry level IP phone

Yealink T20P is the entry level phone, of the Yealink VoIP desk phone range.

The Yealink T20P provides an entry level phone for the Yealink range of VoIP phones. The T20P boasts features beyond what you may expect from the lowest specification of the range. Ideal for use for the home or as a small office phone.

The T20P telephone offers power over ethernet (PoE), two SIP accounts, two line keys and a clear 2x 16 line LCD screen. A cost effective entry level enterprise IP phone with 2 lines.

Strong provisioning is in place for the Yealink range, making the models perfect for ITSP’s or large scale deployments.

Features

T20P-large

  • 2 SIP Accounts
  • 2 Line, 2×16 LCD Display
  • 2 Programmable Keys
  • 5 Hard Function Keys
  • Power over Ethernet (PoE)
  • 3 Way Conference Calls
  • Speakerphone
  • Call Hold, Waiting and Transfer.
  • Wall mountable
  • Compatible with a range of corded headsets:

 

RRP £69.99 +vat , (Contact us for volume and Special pricing)

Categories
Knowledge Base Support

24×7 Asterisk server monitoring with Nagios.

We offer an economical solution for end users and resellers to monitor their Asterisk and Linux servers.

Our platform monitors servers 24 hours a day 7 days a week. Hosted in a state of the art US based data centre with connections to major UK data centres and multiple connections to the internet.

We offer different levels of monitoring from simple uptime and email alerts to system load, disk space and channel usage with email and SMS notification. Web panel and firefox/Chrome plugin available to all levels to view system status.

The service is primarily aimed at Asterisk based IPPBX server but we can monitor other Linux based servers and Mitel systems as well. Our checks on Asterisk servers were customised by us to allow easy and secure deployment as we only require SSH access to make checks and this is secured by server keys. 

Nagios monitor screen

 

Service levels

Silver Level £10 setup – £2.50 per month £25.00 per year

  • Single Server, 4 services from list below & email alerts.
  • Ping test
  • SIP/IAX Peer availability
  • Asterisk channels
  • ISDN availability
  • Disk Space
  • System Load
  • Heartbeat Status
  • SIP/IAX2 registration status
  • Mitel SNMP Alarm status

Gold Level £10 setup per server – £5.00 per month £50.00 per year

  • Upto 2 Servers, 4 services per server, email and SMS alerts by subscription

In addition to the silver list:-

  • Asterisk Database status
  • Custom checks, (cost for design may be inured)

Additional options.

SMS alerts by arrangement, if using Gradwell Numbers and outbound we can integrate with the SMS API

Extra contact £5 setup

Extra server £10 setup £2.50 per month £25 per year

Extra service £5 setup £0.50 per month £5 per year

Partner options are available, Please contact us for details.  Pdf  download cymon