iptel IETF 51

Agenda Bashing Agenda Bashing5m CPL and TRIP Status5m Charter Review10m TRIP for GW10m

CPL and TRIP Status CPL –Still waiting for resolution of calsch issues…. –Continued discussion on list, calsch has a mandate to resolve quickly TRIP –In IESG Review –Have gotten mostly minor comments back from IANA, some reviewers –Incorporated into -08 –Awaiting further feedback/input from IESG

Charter Review Our new charter was approved! Current Work Items –TRIP MIB, due to IESG Sep 01 –Gateway Registration, due IESG Jan 02 For later –CIC Attribute through IANA registration –Discard Authorization until a need is shown

TRIP MIB Update in July Comments?

Gateway Registration Changes since last version –Explicit requirements defined –Comparison with existing protocols –Inclusion of open issues –Removed DSP Capacity

Requirements 1.Fast call setups 2.Conveys failures of gateways rapidly 3.Conveys re-starts of gateways rapidly 4.Proxy has some way to know available capacity 5.Security: mutual authentication, integrity. Privacy less critical. 6.Convey routing preferences 7.Timeliness of attribute information 8.Extensible attributes 9.Efficient 10.Centralization of policy 11.Proxies in ITAD make independent policy decisions

SLP as a Solution Approach 1 –Gateways is a SA –Proxy is a DA –There is no UA Approach 2 –Proxy is a UA –Gateway is a SA –No DA Approach 1 analysis –Meets all the requirements –HOWEVER, effectively makes SLP do what TRIP does –impedance matching would argue for using TRIP-based mechanism

Approach 2 Analysis REQ 11 –Control of gateway selection moves to gateways – in conflict with REQ 11 REQ 1 –Proxy queries introduce latency in call setup General assumptions dont match –SLP assumes many clients, each of which interacts briefly Here, clients are few, prolonged interaction Changes security approaches –Discovery not an issue here, big in SLP

Open Issues Conveying routing preferences –Assumes gateways know their preferred routes, and the proxy doesnt –Is this right? Would the proxy be provisioned directly? Attribute Applicability –Do attributes apply to a route or to the gateway? TRIP assumes routes. –Fine for attributes that are common across routes (codec listing), but not ones that need to be partitioned (circuit capacity!)

Open Issues Attributes –Codecs? –Media Types? –Encryption algorithms? –SIP/H.323 extensions/features? –Others? Name of protocol –Is it still TRIP?