VoIP for Business


  A discussion of issues relating to deploying
Asterisk based VoIP systems in a business setting

    ...
Disclaimer

●   Views expressed are my personal
    opinions, not those of my employer

●   Not affiliated with any vendor...
Presentation Goals

●   Overview of VoIP
●   Business implementation of Asterisk
●   Lessons learned
●   Costs
●   Resourc...
VoIP vs PSTN

●   PSTN
    –   Public Switched Telephone Network
    –   Calls go through physical circuit paths
    –   1...
Why install VoIP?
●   New calling features
●   Better integrate voice & data (CTI)
●   Easier/cheaper administration
●   I...
Open Source VoIP Pitfalls
●   Compared to PSTN, VoIP is immature
●   No single vendor “Turn-Key” solutions
●   More featur...
Why Open Source VoIP?
●   To eliminate vendor lock-in
●   To take total control of system
●   To avoid license costs
●   C...
Why we chose Open Source
●   Cost
●   Speed of deployment
●   Desire to avoid vendor lock-in
●   Wanted to really “own” sy...
Our Requirements
●   Single Building
●   100 employees + conference rooms etc.
●   Receptionist
●   Overhead Paging
●   Vo...
Business VoIP System
                                                                  DHCP
                              ...
Choosing a Prototype
●   Implement a small system for test group
●   Researched OSS & Commercial
    –   Cisco, Nortel, Mi...
Switchvox selected
●   Switchvox targets smaller deployments
●   Vendor support valuable
●   Low cost, Low Risk
    –   St...
Switchvox Pilot Solution
●   Dell 1800 Server
●   Switchvox software
    –   Fedore Core
    –   Asterisk
    –   Propriet...
Test successful but...
●   Analog PSTN interface prone to echo –
    eventually mostly resolved
●   Didn't replicate every...
Pilot Phase II
●   Upgraded to 4 port Digium T-1 Card
●   Excellent tech support from Switchvox
●   T-1 cable was a guess
...
Pilot Lessons Learned
●   Features are split between phone & PBX
●   Phones are “partners” with PBX
●   Configuring phones...
Prep to Deployment
●   Designed PoE Network
●   Chose Telephones
●   Created database to track names,
    extensions, tele...
Business VoIP System
                                                    UPS                   DHCP
                      ...
“Component” Costs
●   Linux - $0
●   Asterisk - $0
●   PBX Hardware - $1,000 ~ $3,000
●   Telephones - $80 ~ $500 each
●  ...
PSTN to VoIP Integration
●   Telcom people don't know VoIP and IT
    people don't know Telecom

●   Be prepared to learn ...
PSTN Interfaces
●   Analog
    –   Analog Telephone Adapter (ATA) – Sipura
    –   Analog Interface card* (Digium)

●   Di...
PSTN Interface - Analog
●   Analog Lines
    –   Good for low external call volume
    –   ATAs are inexpensive
    –   Ec...
PSTN Interface - Digital
●   Digital Lines
    –   T-1 PRI provides 23 circuits
    –   Can be less expensive than same nu...
PBX Server Selection

●   Buy reliable hardware
    –   Redundant power supplies
    –   RAID
    –   ECC memory
●   Moder...
Asterisk PBX Provides

● PBX functions to control calls
● Voicemail

● Call Conferencing

● Music On Hold

● Call Queues

...
Asterisk Configuration
●   Create SIP channels
●   Create PSTN channels
●   Create dialplan
●   Configure voicemail, email...
Telephones
●   Choose SIP
●   Features, Cost & Quality vary widely
●   “Feel” and “Sound” of phones important
●   Message ...
Voice Quality Factors
●   Handset versus softphone
    –   Quality of sound card
    –   Quality of microphone/earphones
 ...
Voice Quality Factors -2
●   Echo
    –   Echo is part of telephone life
    –   Is less with digital (T-1/E-1) PSTN conne...
Telephones – PoE

●   No need for power outlet by phone
●   Reduce cabling at telephone
●   Phones may use bulky, expensiv...
Polycom PoE Cable

           ●   PoE cable is
               9' long
           ●   PoE block is
               1.5' from...
Telephones - Configuration

●   Telephones require configuration
●   Most phones support:
    –   Keypad entry (limited an...
Network - Dedicated/Shared?

●   VoIP needs good networking
●   Shared VoIP & Data
    –   Less cost (only 1 set of switch...
Power over Ethernet (PoE):

●   Two PoE Options:
    –   PoE Switch (Power and Switch together)
    –   Power Injector (be...
VoIP “Sidekicks”

●   Optional but recommended
●   User & telephone database
●   Backup system for PBX config files and
  ...
Username/Password Mania!
●   Phone
    –   password to access Asterisk
    –   password to change in-phone settings
    – ...
More Username/Password
            Mania!
●   Admin
    –   PBX server root
    –   PBX administration interface
    –   T...
Bringing it All Together

●   Build the network
●   Install & configure the server
●   Build the user database
●   Provisi...
Our System

●   Live since October 2005
●   2,000 calls/day
●   $39,000
    –   2 Dell PBX (1 switchvox, 1 just asterisk)
...
Good Luck!
Miscellaneous
“Selling” Management on
                 Asterisk
●   Hire a vendor
●   Positive reviews in PC Mag, E-week etc
●   Demonst...
VoIP Resources
●   www.voip-info.org (wiki)
●   Asterisk mailing list (not for the meek!)
●   Books:
    –   Switching to ...
Resources – Asterisk Training

●   Digium – 3 days, $1,500
●   Signate – 4 days, $1,795
●   Astricon – 5 days, $3,000
Resources – End User Training

 ●   Download telephone manuals
 ●   Create “help sheets”
 ●   Telephone demonstration clas...
Softphone Issues
●   Softphone success depends on
    –   Quality of sound card
    –   Quality of microphone/earphones
  ...
VoIP – Protocols
●   Signaling to control calls
    –   SIP = Session Initiation Protocol
    –   SCCP = Skinny Client Con...
VoIP – Common Terms

●   PSTN = Public Switched Telephone
    Network
●   Central Office = phone company center
●   ATA = ...
Overhead Paging
●   Another Integration Challenge
    –   Speaker System Choice & Design
    –   Cable Installation
    – ...
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VoIP for Business

  1. 1. VoIP for Business A discussion of issues relating to deploying Asterisk based VoIP systems in a business setting Tim Frichtel TimFrichtel at yahoo dot com Scale 4X – February 12, 2006
  2. 2. Disclaimer ● Views expressed are my personal opinions, not those of my employer ● Not affiliated with any vendor mentioned ● I'm not an Asterisk developer
  3. 3. Presentation Goals ● Overview of VoIP ● Business implementation of Asterisk ● Lessons learned ● Costs ● Resources ● Cheap long-distance not covered ● Configuring Asterisk not covered
  4. 4. VoIP vs PSTN ● PSTN – Public Switched Telephone Network – Calls go through physical circuit paths – 100+ years of maturation/optimization ● VoIP – Calls are packetized, carried over IP – Can be peer-to-peer or through a PBX – Systems can be open or proprietary
  5. 5. Why install VoIP? ● New calling features ● Better integrate voice & data (CTI) ● Easier/cheaper administration ● Increased redundancy ● Maybe to reduce long distance costs ● Not to get “better” voice ● Not necessarily to get better support
  6. 6. Open Source VoIP Pitfalls ● Compared to PSTN, VoIP is immature ● No single vendor “Turn-Key” solutions ● More features = greater complexity ● Total control = Total responsibility – For configuration – For testing – For integration – For troubleshooting ● You are the integrator!
  7. 7. Why Open Source VoIP? ● To eliminate vendor lock-in ● To take total control of system ● To avoid license costs ● Choice in: – Phones – PBX Hardware – PSTN Gateways – SIP Service providers
  8. 8. Why we chose Open Source ● Cost ● Speed of deployment ● Desire to avoid vendor lock-in ● Wanted to really “own” system ● Comfort with Linux and other OSS ● No big vendor would do a pilot
  9. 9. Our Requirements ● Single Building ● 100 employees + conference rooms etc. ● Receptionist ● Overhead Paging ● Voicemail ● Conferencing ● A few Fax & Modems ● NOT a call center
  10. 10. Business VoIP System DHCP Backup FTP T-1(s) Asterisk Server PBX Phone Analog line(s) Config & SI iste R eg P r Log Files T-1(s) Asterisk PBX SIP Register Spkr Analog line(s) page Switch gateway SIP Provider (optional) Fax, Modem, Alarm analog Lines
  11. 11. Choosing a Prototype ● Implement a small system for test group ● Researched OSS & Commercial – Cisco, Nortel, Mitel, Zultys, Siemens – Asterisk, Pingtel – Full system quotes - from $85,000 to $110,000 ● Asterisk looked (and IS) hard ● Hybrid OSS/Commercial chosen – Switchvox (based on Asterisk)
  12. 12. Switchvox selected ● Switchvox targets smaller deployments ● Vendor support valuable ● Low cost, Low Risk – Standard Dell Server – Polycom Telephones – Pre-configured to our needs
  13. 13. Switchvox Pilot Solution ● Dell 1800 Server ● Switchvox software – Fedore Core – Asterisk – Proprietary Switchvox Admin Interface ● Digium TDM 400P Analog Card ● Polycom 300 and 600 telephones ● PBX & phones came pre-configured ● It worked perfectly when we plugged it in!
  14. 14. Test successful but... ● Analog PSTN interface prone to echo – eventually mostly resolved ● Didn't replicate every feature of existing Nortel Meridian ● Network and power challenges became obvious ● Pilot demonstrated how involved replacing a 10-year old stable system would be...
  15. 15. Pilot Phase II ● Upgraded to 4 port Digium T-1 Card ● Excellent tech support from Switchvox ● T-1 cable was a guess ● Using phones from other vendors was a steep learning curve – but worked – Cisco 7940 – Grandstream GX2000
  16. 16. Pilot Lessons Learned ● Features are split between phone & PBX ● Phones are “partners” with PBX ● Configuring phones manually is tedious ● Lots of data in a phone system ● “Closed” Switchvox system: – Great at what it does – No direct access to Asterisk – Out of luck if you want to do something it doesn't
  17. 17. Prep to Deployment ● Designed PoE Network ● Chose Telephones ● Created database to track names, extensions, telephone MAC address and PBX passwords for telephones ● Created app to generate XML files to configure Phones ● FTP server for phone configuration files & phone log files
  18. 18. Business VoIP System UPS DHCP Backup FTP T-1(s) PSTN Server Asterisk Interface PBX Phone Analog line(s) Config & SI iste R eg P r Log Files T-1(s) PSTN Asterisk SIP Interface PBX Register Spkr Analog line(s) UPS Switch page SIP Provider (optional) gateway UPS Fax, Modem, Alarm analog Lines
  19. 19. “Component” Costs ● Linux - $0 ● Asterisk - $0 ● PBX Hardware - $1,000 ~ $3,000 ● Telephones - $80 ~ $500 each ● PoE Switch - $800 ~ $3,500 ● UPS for Server and PoE switch ● PSTN Interface $200 ~ $5,000
  20. 20. PSTN to VoIP Integration ● Telcom people don't know VoIP and IT people don't know Telecom ● Be prepared to learn Telecom ● You are the integrator ● Good Telecom support is critical
  21. 21. PSTN Interfaces ● Analog – Analog Telephone Adapter (ATA) – Sipura – Analog Interface card* (Digium) ● Digital (PRI – T1/E1) – Internal Interface Card* (Digium, Sangoma) – External Router (Cisco) Caution! - Internal PSTN cards aren't always compatible with, and may not fit in all PCs/servers
  22. 22. PSTN Interface - Analog ● Analog Lines – Good for low external call volume – ATAs are inexpensive – Echo is a bigger issue – Analog lines cost tens of dollars/month – “Built in” fall-back – plug a telephone in! – Your phone number is tied to Central Office – Expensive for multiple DID (direct inward dial) lines
  23. 23. PSTN Interface - Digital ● Digital Lines – T-1 PRI provides 23 circuits – Can be less expensive than same number of analog – Echo rarely an issue – PRI has more features than analog – Need expensive, specialized test equipment to troubleshoot -- (or a vendor) – T-1 Interface card more expensive, but only real way to go for many DID lines – Channel banks can be used to split analog lines out of T-1 for fax/modem
  24. 24. PBX Server Selection ● Buy reliable hardware – Redundant power supplies – RAID – ECC memory ● Moderate speed is OK ● RAM > 512 (more for conferencing) ● Disk – voicemail is biggest consumer ● Check compatibility with PSTN cards! ● UPS recommended
  25. 25. Asterisk PBX Provides ● PBX functions to control calls ● Voicemail ● Call Conferencing ● Music On Hold ● Call Queues ● Integrated Voice Response (IVR) ● Integration with Data System ● Call Reporting/Logging
  26. 26. Asterisk Configuration ● Create SIP channels ● Create PSTN channels ● Create dialplan ● Configure voicemail, email integration ● Create IVR/Call Queues ● “User Friendly” interfaces are important – Switchvox (can't see Asterisk files) – Sigman (can see Asterisk files) – Asterisk@Home (can see Asterisk files)
  27. 27. Telephones ● Choose SIP ● Features, Cost & Quality vary widely ● “Feel” and “Sound” of phones important ● Message lights, buttons matter ● Headsets support generally integrated ● Check CODEC support ● Power choices – AC Adapter – Power Over Ethernet (may require special cable)
  28. 28. Voice Quality Factors ● Handset versus softphone – Quality of sound card – Quality of microphone/earphones – PC stability and availability ● Codec - G711 – free, high quality & bandwidth – for LANs ● Codec - G729 – licensed, good quality, low bandwidth – for WANs ● Others
  29. 29. Voice Quality Factors -2 ● Echo – Echo is part of telephone life – Is less with digital (T-1/E-1) PSTN connections – Some echo is good (side tone) ● Latency – Delay due to equipment, routing, distance etc ● Jitter – Due to dropped, out of sequence packets ● Dropped Packets – A few lost packets won't be noticed
  30. 30. Telephones – PoE ● No need for power outlet by phone ● Reduce cabling at telephone ● Phones may use bulky, expensive cable ● Only reliable if supported with UPS ● Not available on all phones or ATAs
  31. 31. Polycom PoE Cable ● PoE cable is 9' long ● PoE block is 1.5' from connector ● Must be connected to standard cat-5
  32. 32. Telephones - Configuration ● Telephones require configuration ● Most phones support: – Keypad entry (limited and painful) – In-phone web server – XML file – best way to go ● Typically XML file: – Features – Phone extension – PBX passwords – Multiple PBX registrations
  33. 33. Network - Dedicated/Shared? ● VoIP needs good networking ● Shared VoIP & Data – Less cost (only 1 set of switches) – Less wire / power / space – Quality of Service (QoS) require network skills ● Dedicated VoIP Network – Expensive – “Throwing money at the problem” – Avoids contention with data network
  34. 34. Power over Ethernet (PoE): ● Two PoE Options: – PoE Switch (Power and Switch together) – Power Injector (between phone and switch) ● PoE switches – Are more expensive – Draw more power – Generate more heat – Have louder fans due to heat – May require external power supplies for redundancy
  35. 35. VoIP “Sidekicks” ● Optional but recommended ● User & telephone database ● Backup system for PBX config files and Voicemail ● TFTP, FTP or HTTP server to deliver telphone config files ● DHCP server to provide IP addresses to phones
  36. 36. Username/Password Mania! ● Phone – password to access Asterisk – password to change in-phone settings – password to access FTP site for config files – password for telephone web config pages ● User – Voicemail password – Web interface password
  37. 37. More Username/Password Mania! ● Admin – PBX server root – PBX administration interface – Telephone FTP upload password – Vendor support web site login – Network Switches – Backup server (if separate)
  38. 38. Bringing it All Together ● Build the network ● Install & configure the server ● Build the user database ● Provision the telephones ● Connect to the PSTN ● Train the users
  39. 39. Our System ● Live since October 2005 ● 2,000 calls/day ● $39,000 – 2 Dell PBX (1 switchvox, 1 just asterisk) – 2 T-1 cards (1 per server) – 120 telephones – Dedicated voice PoE network – Overhead speakers for 30,000' office ● Employees happy
  40. 40. Good Luck!
  41. 41. Miscellaneous
  42. 42. “Selling” Management on Asterisk ● Hire a vendor ● Positive reviews in PC Mag, E-week etc ● Demonstrate with low-cost pilot system – Switchvox, Signate, Asterisk@Home ● Demonstrate using multi-vendor phones ● Showcase cool new features – Email a voicemail – Use softphone ● Don't Over Sell!
  43. 43. VoIP Resources ● www.voip-info.org (wiki) ● Asterisk mailing list (not for the meek!) ● Books: – Switching to VoIP (O'Reilly) – Asterisk (O'Reilly) – VoIP Telephony with Asterisk (Signate) ● White Paper – Voice over IP 101 (Juniper Networks) ● Asterisk overview video – revision3.com/systm/ episode #5
  44. 44. Resources – Asterisk Training ● Digium – 3 days, $1,500 ● Signate – 4 days, $1,795 ● Astricon – 5 days, $3,000
  45. 45. Resources – End User Training ● Download telephone manuals ● Create “help sheets” ● Telephone demonstration classes
  46. 46. Softphone Issues ● Softphone success depends on – Quality of sound card – Quality of microphone/earphones – PC stability and availability – PC network ● User reaction – Headsets can be uncomfortable – Not as convenient as physical phone – OK for travel and occasional use
  47. 47. VoIP – Protocols ● Signaling to control calls – SIP = Session Initiation Protocol – SCCP = Skinny Client Control Protocol (Cisco) – H.323 – older, more complex – MGCP = Media Gateway Control Protocol ● Voice Data (“payload”) – RTP = Real Time Protocol
  48. 48. VoIP – Common Terms ● PSTN = Public Switched Telephone Network ● Central Office = phone company center ● ATA = Analog Telephone Adapter – connects analog phones to VoIP ● Foreign Exchange (Station, Office) – FXS = Interface to connect analog telephone device to VoIP – FXO = Interface to connect analog line to VoIP
  49. 49. Overhead Paging ● Another Integration Challenge – Speaker System Choice & Design – Cable Installation – VoIP to Speaker integration ● Cobbled solution works! – Grandstream 2000 phone cut open to feed amplified speaker system ● Better solution coming – Sipura ATA and Bogen TAM-B interface
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