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Voice over IPInterconnect
Stephen KinghamProject Manager and Consulting Engineer, Voice and Video over IPAARNet and CSIRO
[email protected] +61 2 6276 6223
John BarlowNetwork EngineerAARNet
[email protected] +61 2 6276 6903
Who is AARNet and CSIRO• CSIRO
Is Australia’s premier government research organisation, only partially government funded.http://www.csiro.au
• AARNetIs the Australian Academic Research Network, linking Australia’s Universities, premier research and cultural centres to the internet.http://www.aarnet.edu.au
AARNet VOIP Building Blocks
Reliability QoSM onitor
PABXVoIP
GATEW AY
GATEKEEPERTransla te te lephone num bers to IP
addresses
AARNetInternet with
QoS bandwidth
PSTNCarrier
VoIPGATEW AY
IP TelephoneH.323 Terminal
H.323PROXY
Otheradvanced IP
network
BillingSystem
Based on ITU H.323 standards
H.323PROXY
AARNet VoIP Service, Now• Supports all telephony destinations, Toll-by-
pass and feature transparency is core business.
• Savings range up to 90% off RRP.• Traffic: connects around 16,000 telephone
calls per day, and growing.• Uses a root Gatekeeper and some feeders.• AARNet backbone supports QoS.• QoS is policed at ingress – accesslist (yuk).• VoIP hackers are policed – accesslist (yuk).• Billing system, based on calling IP address.• QoS network management actively changes
H.323 routing around problems.• Test lab
Test Call Scenarios
PABXVoIP
GATEW AY
GATEKEEPERTransla te te lephone num bers to IP
addresses
AARNetInternet with
QoS bandwidth
PSTNCarrier
VoIPGATEW AY
IP TelephoneH.323 Terminal
PABX
In dial exchangelines or CAS
• Test key call scenarios and• PABX/IP Telephone alternate route
under all failure conditions
H.323PROXY
“TOLL BYPASS” Business Model
PABX AARNetInternet PABX
Firstchoice
Public SwitchedTelephone Network
Carrier
Hop off points for AARNet Members
AARNet
PSTNBrisbane
PSTN
Perth
PSTN
Adelaide
PSTN
Melbourne
PSTN
Canberra
PSTN
Sydney
GatekeeperUSQ
CSIRO
QUT
ACU
UQ
Ade Uni
CSIRO
Flinders
Sydny
CSIRO
ACU
Uni WA
CSIRO
La Trobe
CSIRO
Uni Mel
Ballarat
VUT
Deakin
Swinburne
Canberra
CSIRO
ANU
USQ
CSIRO
QUT
ACU
UQ
Ade Uni
CSIRO
Flinders
Sydny
CSIRO
ACU
Uni WA
CSIRO
La Trobe
CSIRO
Uni Mel
Ballarat
VUT
Deakin
Swinburne
Canberra
CSIRO
ANU
AARNet VoIP, Tomorrow Research VoIP interconnects between carriers. VoIP interconnect pilots with research institutions
in US, Korea, Singapore, Czech Republic, Brazil. VoIP interconnect with two Australian Carriers. Implement a smarter Gatekeeper. Get H.323 proxies working in production. Change method of policing QoS. Change method of authorising VoIP calls. Change billing system to be based on bytes
rather than time (both ends pay …). Support IP Telephones. Support VIDEO as well as audio (native as well
conferencing and gateways back to ISDN).
Some key lessons
• Resource QoS implementation and support as much as the VoIP.
• Use VoIP to switch call, do not use PABXs.• Reduces faults in private telephone
networks.• VoIP using G.729 is resilient against
packet loss.• Enabling QoS to get over the brief periods
of congestion is needed, even on Gigabit.• Billing model need to change from
traditional telephony to data constructs.
Basis of the Charging Model
CALLINGMemberPABX
AARNetANSW ERING
MemberPABX
Rx datacharge 1c/min
Rx datacharge 1c/min
CALLINGMemberPABX
AARNetAARNet transit
VoIP router
Rx datacharge
Rx datacharge
PublicTelephone
Carrier
Local CallCharge
Rx data charge andthe call charge
On-net
Hop-off
See http://voip.aarnet.net.au/AARNet
Some key lessons
• Although peak bandwidth per call is 24kbps, in practice it is on average 5kbps (using G.729), do your own maths on the cost!
• Huge changes looming for management of basic telephony. AARNet has started a working group to assist migration from PABX to IP Telephones.
VoIPMonitor TOPOLOGY
• Monitor links to each RNO, and• Links to each member.• Shutdown destinations that fail.• http://lattice.aarnet.net.au/VoIPMonitor
TEST
TEST
TEST
TEST RNO
RNO
RNO
Member
Member
Member
Member• Client only tests
local links
Some key issues for VoIP interconnect.
• H.323 proxies appear to be the answer for solving these key issues:• Providing access between domains, or
Internet into LAN based IP telephones.• Policing use of QoS.• Authenticating who is making the VoIP call.
• Gateways need to authenticate VoIP calls through an intelligent Gatekeeper or a clearing house sever using OSP.
VoIP Carrier Interconnection
VoIP PSTNITU-TSS No 7PSTN PSTNITU-TSS No 7VoIP ITU-TSS No 7 VoIPVoIP Proxy VoIP
•Signalling system number 7 is not appropriate for VoIP
Outgoing calls from site
ProxyIP Telephone
Firstchoice
PABX PSTN
Extension
AARNetInternet
Gateway
Interconnection
Safety of Life
• Emergency Service providers rely on knowing WHERE someone is, not who. How do we do it????
QuestionsContact Details, and Thank you
URL: http://www.aarnet.edu.au/
[email protected] +61 2 6276 6223Mobile +61 419 417 471
[email protected] +61 2 6276 6690
