(VoIP)-Definition• What is this? – Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies for delivery of voice communications over the Internet or other packet-switched networks. Other terms frequently encountered and synonymous with VoIP are IP telephony and Internet telephony, as well as voice over broadband, broadband telephony, and broadband phone, when the network connectivity is available over broadband Internet access. – VoIP systems usually interface with the traditional public switched telephone network (PSTN) to allow for transparent phone communications worldwide.
VoIP Types• IP-PBX -Pure IP to IP endpoints -Architecture Centralized or Distributed Call Processing - “Hosted” IP-PBX applications• IP-Enabled PBX – Digital PBX’s with Ethernet Trunk Cards/Gateways - Ease of Migration to IP
VoIP Architectures• Centralized – Call processing, voice mail, and applications are centralized at one location with transport /access across WAN or public/private connections • Call processing can be redundant in this model at two locations for primary/secondary backup • Uses more WAN bandwidth due to call switching being centralized• Distributed – Call processing is provided at each site – Voice Mail and applications generally centralized but can also be distributed – Increased reliability since each site will function if WAN or carrier lines fail – Only uses WAN bandwidth for Intra-WAN calls
VoIP Models• Internal/Standalone – Isolated school, building, or campus• WAN Model – Schools in a district utilize VoIP across the WAN to tie together their sites, lines also pooled centrally• IU/Regional Service Center Model – These centers can tie together individual IU’s, or IU’s to each district, or County wide centers to each district• Hosted Services Model – can tie together various entities thru Carrier based connections, or the Internet to provide VoIP services with little or no on-site VoIP equipment
VoIP-WAN Model- Distributed Server Voice Mail PSTN Auto-Attendant Workgroups CentralizedLines- PSTN backup PRICall Detail Recording Management IP IP Network Network Server PSTN Voice Mail WIDE Auto-Attendant IP AREA Workgroups NETWORK IP Call Detail Recording Network Management Network PSTN PSTN IP Network PSTN Distributed Call Processor Switch( typ. Each site)
VoIP Model-IU/Regional Service Center Centralized All Calls switched thruPSTN Central Site/All Voice Mail accessed from Central Site IP Call Manager-backup Network Call Manager-primary Server School District Voice Mail Auto-Attendant Workgroups Call Detail Recording Management IP Network School District IP NetworkPSTN PSTN WIDE AREA IP NETWORK Network Intermediate Unit or School District Regional Media Center PSTN IP CentralizedLines-Backup Survivable Network PSTN backup PRI Gateway(typ.) School District PSTN Catalyst 3750 SERIES 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 1X 11X 13X 23X SYST RPS MASTR STAT DUPLX SPEED STACK 1 2 MODE 2X 12X 14X 24X PoE Layer 2/3 Switch(typ)
VoIP Model-IU/Regional Service Center Distributed All Calls switched Locally/ All Calls switched thruPSTN Central Site/All accessed All Voice Mail Voice Mail accessed from Central Site from Central Site Intra-System Calls IP between sites and VM Access and primary Network calls thru PRI School District Server(s) Voice Mail VoIP Switch/Call Call Detail Recording Processor-Local Management IP Network School District IP NetworkPSTN PSTN WIDE AREA IP NETWORK Network Intermediate Unit or School District Regional Media Center PSTN IP CentralizedLines- Network PSTN backup PRI-ISDN PRILocal Survivable School District Gateway(typ.) VoIP Switch/Call Processor-Local PSTN Catalyst 3750 SERIES 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 1X 11X 13X 23X SYST RPS MASTR STAT DUPLX SPEED STACK 1 2 MODE 2X 12X 14X 24X PoE Layer 2/3 Switch(typ)
VoIP Model-IU/Regional Service Center-Hosted Services Note handsets are Leased or All Calls switched thru Call Manager(s)/ provided by the Owner Carrier Site/All Voice Mail Call Switching and Services accessed from Equipment PSTN Carrier Site Server(s) Voice Mail Auto-Attendant IP Workgroups Network Call Detail Recording School District Management Other Services IP Hosted Carrier Network PSTN IP Network Centralized Lines-PRI/ISDN School District IP PSTN Network PSTN WIDE AREA IP NETWORK Network Intermediate Unit or 911 Calls( Typ.) School District Regional Media CenterPSAP PSTN IP Backup Survivable Network PSTN backup Gateway(typ.) School District PoE and QoS PSTN reuirements(typ.) Catalyst 3750 SERIES 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 1X 11X 13X 23X SYST RPS MASTR STAT DUPLX SPEED STACK 1 2 MODE 2X 12X 14X 24X PoE Layer 2/3 Switch(typ)
Why Implement ?• “Converge” the Network – Leverage bandwidth of GIGE or higher networks and optimize infrastructure – Eliminate legacy equipment and faulty cabling systems – Video over IP and Video Conferencing over IP – Eliminate physical MAC’s of PBX systems – Consolidate maintenance contracts under IT – Consolidate lines and save $$ – Unify Dialing Plans – Centralized Services to reduce costs • Intra calls within Regional WAN may remove toll charges
Why Implement ?• Applications that may benefit – Unification of Voice Messaging with email – Increased Accessibility of Teachers and Staff • Find Me/Follow Me – Phone Directories become electronic – DID’s provide direct connect calls and direct inward faxing capabilities – Caller ID can be provided for ANI, tracing bomb threats, etc. – IT technicians and others can roam and be mobile with “soft” phones and/or WI-FI/cell phones – Single network to manage
Planning• What voice service/carrier contracts are in place now?• Do you want to centralize services?• What is bandwidth of current WAN’s/LAN’s? – Do you need an Infrastructure Upgrade?• What types of network equipment do you have now?• Can you implement QoS and/or bandwidth reservation mechanisms on your WAN’s now?
Planning (cont’d)• Traffic Studies – Plan capacity of voice traffic across links and compare to network traffic to assure sufficient bandwidth – Run Link tests using monitoring software to have baseline of data traffic• Power Issues – UPS and/or Generator backup will be required in each closet where VoIP will be employed – Cooling of closets may be an issue due to increased heat load• Equipment Issues – Network gear needs to support VLANs and QoS or CoS, and Core switches to support Layer 3( and/or Layer 4 prioritorization) – Power over Ethernet( PoE) will need to be provided using switches or mid-span products• Interfaces – Public Address, Night Ringers, Cabling to tel. demarcs, number portability, Faxes, Fax servers/Analog connections
Planning (cont’d)• Do Inventory the network connections, bandwidth, all network gear, number of phones/phone users, outside lines/trunks/types, UPS systems, and current telephony equipment and systems• Determine if network gear will support QoS/PoE/VLANs and if it is L2 or L3 or L4• Do run a VoIP network assessment test from software or vendor services prior to implementation• Redundancy-Can you add redundant links or systems in case of failure or disaster• Network Security- Protect servers behind Firewalls, use Voice VLANs to isolate traffic, use VPN’s and/or encryption over the Internet and/or unsecure links, physically secure servers..
Planning (cont’d)• Quality of Service( QoS) – Layer 2 is CoS prioritorization-IEEE 802.1Q( VLAN tagging) and IEEE 802.1p( 3 bit PCP field) • IP Precedence using 3 bit PCP field( 8 classes) • HOW MANY CLASSES DO THE SWITCHES SUPPORT NOW?( four/port is good, eight/port is best) • IP Phones typically “stripe” at class 5 for CoS marking in Layer 2 Ethernet frame – Layer 3 is DSCP( differentiated services code point)- DiffServe uses TOS field in the IP field – Layer 4-can prioritize by UDP port #?
Planning (cont’d)• Network Requirements – Should use Voice VLANS( by subnet) – Use DHCP and separate scopes for Voice VLAN subnets – Use L2/L3 switches instead of routers – Use 64K compression G. 711 where possible – Implement QoS – Packet Loss less than 1% – Average Jitter less than 30ms – One Way Delay no more than 150 ms – Priority Bandwidth needed per call ~ 106-120kbps
Planning-Summary• Feasibility Study/Assessment – Survey – Analysis/Testing – Options/Costs – Final Recommendations – Select next steps for Implementation and pre- liminary schedule – Select Vendor here( if possible)
Challenges• Must get a good “picture” of current network (s), and any traffic statistics on links and WAN links – Test if possible• Determine “Physical” impact – Do you replace switches and routers? (remember PoE impacts) – Cabling( Cat. 5 min. to the desk)/ connecting backup lines to MDF – UPS and Power needs for backup – Locating and backing up central equipment/local equipment – Are there still analog phones to be connected? – Must get a good phone count – Phasing of the Network in cutover• Determine “Logical” impact – VLANs/ DHCP scopes/New subnets/Layer 2 and Layer 3/Security• Additional support/personnel needed from IT to run and maintain the VoIP on the network• May not always save $$ by doing VoIP-even if centralizing• Increase in network complexity by adding voice and “converging”• Convincing Management to spend the $$
Implementation• Develop Final RFP/RFQ• Bids and obtain quotes• Vendor negotiations for material and labor• Make sure Owner ancilliary equipment provided ahead of time or in coordination with implementation-UPS’s. cabinets, cabling, demolition, etc.• Coordinate IP Addressing Schemes and changes• Start-ups/Cutovers• Training very important- can “train the trainer”• Include MOS (mean opinion score) testing- must have at least 4.0 or above for toll quality voice per ITU- P.800/SLA Metric
Pitfalls to Avoid• Do not solely rely on one Vendor• Don’t overlook the aspects of the physical/logical infrastructure and the impacts needed to support VoIP• Don’t try to oversubscribe the bandwidth and not implement QoS mechanisms• Don’t implement without network assessment testing and running a pilot project for a proposed manufacturer• Don’t overlook training of users and additional support that will be required
Costs• Hard Costs – typical~ $600 to $800 per IP Phone to implement for VoIP only( does NOT include data network upgrades) – Data Network upgrades~ $150 to $300/Ethernet Port( includes PoE)• Soft Costs – Yearly maintenance cost of 15 to 28% /year-varies – Consultant Fees• Hidden/Overlooked Costs – ISDN PRI/DID block monthly costs( e-Ratable) can vary ~$600/mo – Cost for Voice Traffic studies from current carriers – Additional Staff needed to maintain/administer new VoIP system – Mechanical/Electrical upgrades required in closets – UPS’s, Cabling, Cabinets, Paging Adapters, Misc., etc. – Servers required to be purchased by Owner
Costs-Example Project Cost Example Consultant, $43,000.00 , 5% Infrastructure, Cisco Data,$129,135.00 , 14% $332,000.00 , 36% Cisco VoIP, $408,447.01 , 45%Cisco Data Cisco VoIP Infrastructure Consultant 621 IP Phones
Lessons Learned• PLAN,PLAN,PLAN!• Keep a Contingency in the Budget !• Decide who is doing what and each responsibility, clear contracts with the Vendor• Keep Training Simple for Users and schedule ahead – Phones – Voice Mail – Unified Messaging• Include all costs to the Owner• Procure Owner provided equipment in early• Physically Identify patch panels/ports ahead of time for any physical cuts, re-patching, reconnections• Allow for ample time for cutovers-”Murphy” is always around