Asterisk

1
Asterisk VoIP

• and its role in your enterprise

2
Asterisk?

• Open-source software released under the GPL
• Sponsored by Digium, the main hardware provider
  for POTS interface cards
• Digium named in the top 10 open source companies
  to watch by networkworld.com
• Ports for most nix systems including Solaris
• Ports also available for OSX and Windows
• Open standards along with some proprietary
  protocol support (like Ciscos Skinny and MGCP)
• Modular plugin type system

3
Protocols Supported

• SIP Session Initiation Protocol
• H.323 Common in video conferencing
• Skinny Cisco IP Phones default protocol
• MGCP Media Gateway Control Protocol
• IAX - Inter-Asterisk Exchange Protocol

Codecs Supported

• G.711 Best voice quality 100Kbps
• G.729 Good voice quality 40Kbps
• GSM Acceptable voice quality 10Kbps
• G.722, G.723.1, G.726, iLBC, Linear, LCP-10,
  Speex

4
PSTN Interface Support

• Analog
• FXO
• FXS
• EM (w/ or w/o Wink), Loop start, Ground start,
  Kewl start
• T1
• EM (w/ or w/o Wink)
• Robbed bit
• ISDN (PRI BRI)
• 4ESS
• Lucent
• National
• Some international support

5
Biggest Features

• Unified Voicemail
• Voicemail to email (.wav files)
• Video Conferencing messages to email (.mpg/.avi
  files)
• Advanced Meetme conferencing - conference
  bridging
• Web management interface
• Support for conference numbers and passwords
• Presenter and Presentee support (presenter can
  mute all participants, etc)
• Contact Center Queuing
• Interactive Voice Response
• Automated Attendant
• Video Conferencing (SIP and H.323)
• Jabber / Google Talk integration
• Find me / Follow me
• Out of state DIDs (all VoIP systems)
• Call monitoring and recording

6
Normal PBX Features

• Name it, its there

7
Enterprise Features

• Unified dialplan across many servers
• SQL Compliant databases (through ODBC)
• Native support for Mysql
• LDAP integration
• DNS SRV records
• Make calling each other easy (adam_at_bblisa.org)
• Scalability
• Load balancing
• Phone provisioning
• DUNDI Distributed Universal Number Discovery
• Works with SIP proxys to accept large amounts of
  phone registrations
• AGI Extend your system using C, C, Perl, PHP,
  
• Custom CDR Used for calling card integration,
  billing,

8
Asterisk Compatible Endpoints

• Cisco IP Phones (except IP 7920)
• Polycom IP Phones
• Snom IP Phones
• Avaya IP Phones
• Linksys IP Phones
• Many others

Asterisk Compatible Gateways

• Cisco VoIP Gateways (anything MGCP, SIP, H.323)
• Cisco Callmanager (through SIP and H.323)
• Patton Smartnode

9
Asterisk PSTN Interfaces

• Digium
• Analog (up to 24 channels on a single PCI card,
  FXO and FXS) with hardware echo cancellation
• T1 / PRI / BRI 1-4 on a single PCI card with
  hardware echo cancellation
• Sangoma
• Better analog support, but uses more PCI slots
  (or spaces)
• T1 / PRI / BRI 1-8 on a single PCI card with
  hardware echo cancellation
• Clear channel DS3
• Any SIP / H.323 compliant endpoint
• Cisco x8xx series ISR routers

10
Possible Asterisk Configurations

• Full PBX
• Add small remote sites onto traditional PBX
• Trunk Routing Gateway
• Toll Bypass Only
• Service Component

11
Full PBX
12
Traditional PBX with Remote Offices

• Use of Digium appliance
• Cisco x8xx routers

13
Trunk Routing Gateway

• Connect a traditional PBX to services like Sprint
  SIP Trunking

14
Toll Bypass Only

• Connect Traditional PBXs together over WAN Links

15
Service Component

• Meetme Conferencing Bridge
• Voicemail / Unified Messaging
• Add Softphones to non-VoIP PBX

16
Drawbacks

• No PCI-Express Support (just came out for digital
  interfaces, still none for analog interfaces)
• Hardware sizing information hard to find
• Kernel updates break Digium drivers
• PCI Bus sharing can cause significant problems
  with voice quality
• NAT Traversal (common across any SIP system)
• Linux system QoS not very mature yet
• No VoIP security yet, although planned
• Not for nix beginners

17
Support

• Certifications dCAP (Digium Certified Asterisk
  Professional)
• Voip-info.org (VoIP WIKI site)
• Commercial support (through Digium)
• Partners (certified or un-certified)
• Mailing Lists (very active)
• User Groups (although none in Boston)
• Astricon (Asterisk conference)
• Books

18
Where to start?

• www.asterisk.org (Asterisk main page)
• www.asterisknow.org (Asterisk and CentOS with
  full installer)
• www.voip-info.org (huge resource for VoIP related
  projects and configuration info)
• www.digium.com (hardware manufacturer and project
  sponsor)
• Trixbox (formerly Asterisk _at_ HOME)
• User Groups Find one close or we can try to
  start one
• Books OReilly, Asterisk for Dummies, Asterisk
  configuration guide,