Transcript Should SIP be modified for per call billing?

Should SIP be modified to
enforce per call billing?
Christian Huitema
Architect, Windows Networking
Microsoft Corporation
Why would we want to
track usage?
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To bill for time, distance
To allocate costs
To predict network traffic
To account for gateway usage
Should we charge for
Telephone Access? Yes!
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Telephone URL:
“tel:12345678901”
User directs “tel:” to
selected service,
Service checks user
authentication, relays
to “Phone-x”
Phone-x completes
the call, bills service
Service bills user.
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SIP works just fine
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Phone-x
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RV
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Should we charge for IP
network usage?
A
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B
Plain traffic? No, or not more than basic
service!
Premium traffic? Possibly!
How to charge for
premium network usage?
B
A
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Plain accounting, no control
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Application level control
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User marks TOS bits, network keep tabs.
Side effect of call set-up, authorizes access.
Network access control
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RSVP transaction, authorizes access.
Pros and cons of three
strategies (1)
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User based TOS:
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Easy to implement, but…
Only feedback is monetary, monthly
No protection against temporary
congestion.
Pros and cons of three
strategies (2)
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Application level control
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SIP is not just for voice
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Feedback on a call per call basis,
What of mid-call congestion?
Need to derive network data from
application data (fragile!).
INVITE to Chat Room, Video Game
Need decision for each media?
SIP proxy need not be colocated with
network access!
Pros and cons of three
strategies (3)
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Network access control
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SIP is not just for voice
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RSVP is designed to pass “network
level” signalling
Can use “pre-condition” in SIP
Use QoS if and when needed
Different decision for every media!
Remote SIP proxy
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Use existing AAA framework to bill user
of remote service
Let’s not pollute SIP,
keep a simple framework!
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SIP already enables billing for
gateways, services.
SIP is not just for voice, we don’t
need to mimic the POTS behavior.
Billing network resource is better
handled by network protocols, RSVP.