… and possible roles of the NRN
VoIP scenario’ s within NRN
networks
Introduction
• The word ‘ VoIP’ both covers a lot of technologies and a lot of possible usage scenarios which lead to confusion
• This document gives an overview of VoIP scenarios that
NRNs can encounter and decribes possible roles of the NRN for each scenario:
0) Traditional Campus infrastructure 2) VoIP on the Campus
3) VoIP between Campus locations 4) Trunk termination
5) Outsourced PBX
Campus
0) Traditional Campus infrastructure
PBX
Rest of Telephony
1) VoIP on the campus
• Instead of a traditional (TDM) PBX, a VoIP-based iPBX dispatches all telefphone traffic
• Telephones are connected to the iPBX through the institutional LAN
Campus
1) VoIP on the campus
LAN
iPBX
Rest of Telephony
1) VoIP on the campus
• Role: – None
– Optional: consulting • Case for the institution: – Using existing LAN
(but: sometimes separate LAN necessary) – Advanced features
– Integration with institutional services (CRM etc) – Easy to work from home (VPN necessary)
2 VoIP between locations
• Instead of sending calls between different locations of one institution ISDN, this can be done over VoIP over NRN.
• If the institution has PBXs
2a VoIP between locations
NRN Location 2 PBX GW Rest of Telephony world Location 1 PBX GW Other call s Internal calls Other calls
• If the institution has a iPBX
2b VoIP between locations
Location 2 Location 1 iPBX LAN LAN NRN Rest of Telephony world Internal calls Other calls
2b VoIP between locations
• Role: – None
– Optional: consulting • Impact
– Availability of the network should be high – Network should be collision free
(so have low latency and jitter) • Case 2a for institution:
– Investment: 2x gateway – Maintenance cost (low)
– Savings: inter-location call costs • Case 2b for institution:
3a) VoIP trunk termination
• Instead of sending calls from an institution to an outside destination (PSTN) over ISDN, this can be done over VoIP. NRN transports VoIP traffic to a commercial carrier that takes care (‘ terminates’ ) it.
• Two ways to connect the campus:
– A) iPBX: delivers VoIP to the WAN
– B) PBX: a gateway converts TDM calls coming from the PABX to VoIP, which delivers VoIP to the WAN
NRN
Campus
3a) VoIP trunk termination
iPBX Rest of Telephony world Carrier GW Call Control Campus PBX GW
3a) VoIP trunk termination
• Role
– IP carrier • Impact
– Availability of the network should be high – Network should be collision free
3b) VoIP trunk termination by NRN
• Instead of sending calls from an institution to an outside destination over ISDN, this can be done over VoIP. NRN
transports VoIP traffic to a commercial carrier that takes care (‘ terminates’ ) it.
• Two ways to connect the campus:
– A) (i)PABX delivers VoIP to the WAN
– B) a gateway converts TDM calls coming from the PABX to VoIP, which delivers VoIP to the WAN
NRN
3b) VoIP trunk termination
Rest of Telephony world GW Call Control Campus iPBX Campus PBX GW
3b) VoIP trunk termination
• Role
– IP carrier – Voice carrier • Impact
– Availability of the network should be high – Network should be collision free
(so have low latency and jitter)
– NRN might be considered a Voice carrier by regulator, meaning that NRN should at least support
• Number portability • Lawful intercept
– NRN should find cheap carriers to terminate traffic or even participate in ‘ wholesale minute market’
4a) VoIP as outsourced service
• An institution does not have an (i)PBX of its own, but rents
phones including a telephone number for its employees and/or students from Service Provider
• Institution receives a monthly bill for rent and calls
• Service Provider provides call control, institutional number plan, advanced features, termination, end-user support and billing
4a) VoIP as outsourced service
Rest of Telephony world Campus LAN WAN (NRN) Service Provider GW iPBX4a) VoIP as outsourced service
• Role
– IP carrier • Impact
– Availability of the network should be high – Network should be collision free
4b) VoIP as outsourced service by NRN
• An institution does not have an (i)PBX of its own, but rents
phones including a telephone number for its employees and/or students from NRN
• Institution receives a monthly bill for rent and calls
• NRN provides call control, institutional number plan, advanced features, termination, end-user support and billing
NRN
4b) VoIP as outsourced service by NRN
Rest of Telephony world Campus LAN GW Call Control
4b) VoIP as outsourced service by NRN
• Role
– IP carrier – Voice carrier • Impact
– Availability of the network should be high – Network should be collision free
(so have low latency and jitter)
– NRN is concidered a Voice carrier by regulator, meaning that NRN should at least support
• Number portability • Lawful intercept
– NRN should find cheap carriers to terminate traffic or even participate in ‘ wholesale minute market’
– NRN should bill its costumers depending on a tariff model (per minute/flat fee)
– NRN should have end-user support desk – Billing
5) VoIP-VoIP routing by NRN
• Inter-institutional VoIP-VoIP calls can be routed by NRN independent of VoIP-to-PSTN traffic flows
• PBX: gateway at campus necessary • iPBX:
– H.323: through GDS (already in place) – SIP: under development at NRN
5) VoIP-VoIP routing by NRN
NRN Call Control Campus iPBX Campus iPBX Campus PBX GW Rest of Telephony world Option 0, 2 or 35) VoIP-VoIP routing by NRN
• Role
– IP carrier
– Call Control/Trusted Third Party • Impact
– Inter-instutional traffic is small
– Bussiness case to place gateways at campuses that don’ t have VoIP has proved negative previously
– Availability of the network should be high – Network should be collision free
Other roles
• Extend functionality (to the end user): IM/Presence
• Authentication infrastructure to authenticate end-users • Authorisation infrastructure to control sessions
• VoIP retail/end user services like – Pilmo.nl
– Optibel.nl
• Not considered: closed VoIP systems like: – Skype
– VoIPster
Combinations of roles
• Connecting a Campus to the outside world can be done in different ways: * = gateway necessary v v* VoIP v v ISDN30 iPABX PABX Type of PABX Termination
Legenda and Abbreviations
• GW Gateway, TDM-to-VoIP gateway
• iPBXIP-based PBX (‘ VoIP PBX’ )
• PBX Public Branch eXchange
• PSTN Public Switched Telephone Network
• TDM Time Division Multiplexing, traditional telephony • VoIPVoice over IP, internet telefphony
IP connection TDM connection IP trunk
IP phone TDM phone