Attributes for GW registration

• E.164 prefix, of course

• Available Circuits

• Total Circuit Capacity

• Call Success Rate

• Carrier-Trunk Group

Available Circuits• Represents the number of circuits currently available for

the set of prefixes in question• Changes dynamically. Not much value in reporting small

changes in availability.• Reporting should be subject to:

- Minimum reporting interval - Can be reported as a second derivative of the

Available Circuits. This makes reporting adaptive to changes in the attribute

- Thresholding on the gateway. This is designed and customized based on the requirements of the particular network

• Not appropriate to disseminate beyond the first-hop LS

Total Circuit Capacity

• Represents the total number of circuits available for the set of prefixes in question

• Relatively static. Hence, this information could be propogated beyond the first-hop Location Server

• Can be effectively used in combination with Available Circuits for gateway selection

Call Success Rate

• Represents { No. Successful Calls, Total Call Attempts } as an ordered pair

• Motivation drawn from ASR (Answer to Seizure Ratio) used in PSTN. Difference is, definition of call success determined based on Reason for Call Disconnect (Disconnect Cause code). Ex: A call that was alerted but did not connect is counted as successful. Similar for a call that got disconnected b’coz the called party is busy

• Reported as an exponential moving average over previous time quantums

Carrier-TrunkGroup• A 2-part attribute. First part

represents the Carrier (or Provider) offering service for the set of prefixes in question. The second part reflects the specific group of trunks in that carrier used for these prefixes

• There is value in propogating this information beyond the first-hop LS. Both Carrier and Trunk Group may be disseminated within the Provider’s network (ITAD). The Carrier information may be advertised between providers (E-TRIP) subject to policy agreements with each neighboring provider

{Carrier A, Trunk2}

{Carrier B, TG 1}

{Carrier C, Trunk 1}

{Carrier C, TG 1}{Carrier A, Trunk2}

{Carrier A, TG1} {Carrier B, TG 2}

LS

What have we accomplished with Carrier-TrunkGroup ?

A Location Server can now route calls based on a combination of E.164 prefix and Carrier (/Trunk Group).

PSTNCarrier A

PSTNCarrier B

PSTNCarrier C

PSTNCarrier B

PSTNCarrier D

VVV

V V

A sample VoIP provider Network

VPSTN gateway

Proxy Server

Pricing

• Advertise Pricing?

Computation of pricing can get quite complex and dependent on several factors. Could result from agreemeents between collaborating providers, sharing minutes, etc.

• Hard to represent the complex interplay of factors that determine this. Then there are currency representation issues. It is best left out at this time.

• If Pricing expressed just by itself adds any value in specific deployments requires further investigation

Thought on Dynamic attributes

Are some of these dynamic characteristics discussed, like Capacity, attributes of gateways or attributes of prefixes?

They are attributes of Carrier/TrunkGroup

What next?

This slide is yet to be filled to reflect any work on attributes going forward