| Thread Links | Date Links | ||||
|---|---|---|---|---|---|
| Thread Prev | Thread Next | Thread Index | Date Prev | Date Next | Date Index |
|
One of the main purpose behind these IEs is to aid in handover decision
making, i.e to help the policy engine in selecting the appropriate network and initiating handovers. Information about availability of high level services can influence
this decision making, however a lot of these elements within HLSI as currently defined are questionable
and it’s not clear if we really need them. Also in terms of IEs we need to separate the ones which are media
independent from the ones that are media dependent. The IEs that are media independent currently include: { Network_Operator, List of Networks Supported, Location,
Roaming_list_Availabale, Neighbor_reports_Available } The media dependent IEs currently include: { Cipher_Suites, Authentication_Methods, Cost (free/not free), IP_Version,
Data_Rates, QoS, Neighbor_Maps } We could use a basic TLV format to represent these, along with a simple
mechanism to query or set the values, of different IEs, so not sure why we really need a basic schema and an extended
schema and all the other baggage along with it. Best Regards, -Vivek -----Original Message----- I am currently writing up a contribution to revise Information Service sections and I have the following questions: The HLSI IE defines several flags indicating the available higher-layer services including ISP, MMS, IMS, MIP, VPN, SIP and NAT. - What is the exact meaning of "VPN support"? Does it
mean that if you connect to the PoA then all data traffic will be automatically forwarded to some remote network over a dedicated tunnel between the PoA and the remote network? Or does it mean that the network
provides a VPN gateway? Or does it mean that the mobile terminal connected
to the PoA can establish a VPN connection to any VPN gateway. Or something else? The first definition does not make sense because
you will need additional information about the remote network to make a handover decision. The latter two definitions do not make sense either, because there are several different ways of establishing a VPN connection (i.e., IPsec, SSL, L2TP, PPTP, etc.) and you will need additional information as to which VPN method is used to make a handover decision. - What is the exact meaning of "SIP support"? Does it
mean that the network has a SIP server or proxy, or something else? - Do we really need HLSI IE defined in the basic set? I think it
can be defined in extended set. This is because we might need more detailed information about higher-layer (such as IP addresses and prefixes of access routers, supported IP mobility optimization mechanism, list of supported ISPs, etc.) to make a higher layer information and just defining a set of flags seems like a half-baked solution. Such detailed information can be provided via
schema-based query by which various higher-layer (and lower-layer) MIB objects can be retrieved once converted to RDF data. Regards, Yoshihiro Ohba |