ForCES TML Service Primitives

<draft-ietf-forces-tmlsp-01.txt>

Weiming Wang, wmwang@mail.zjgsu.edu.cn Jamal Hadi Salim, hadi@znyx.com

Alex Audu, alex.audu@garlandnetworx.com

Slides made: Weiming WangNov 7, 2006

Purpose of the document

• In a standardized way to describe TML services– that PL expects to get from any TML

– that individual TMLs or their implementations must provide

Objectives

• Define TML services for:– unicast, multicast and broadcast PL message

delivery (send and receive)– notification of TML events like errors and

congestion state (required by TML requirement)– synchronous and asynchronous operations. – other services that PL expects any TML does

Describe a TML

• TML event– TML error event

error type: • all local TML link failure

• some local TML link failure

• peer TML unavailable

• peer TML abnormally left

• etc

– TML message arrive event• asynchronously notify PL of message arrive

Describe a TML

• TML event (cont’d)– TML congestion alert

• report a congestion alert with an alert type

possible congestion alert type: • congestion alert from control message transmission

• congestion alert from redriect message transmission

• alert from redirect DoS attack

Describe a TML

• TML capabilities– Supported TML type

TML media types the TML supports represented by a TML type id list.

possible TML type with the id:

1 TCP+UDP

2 TCP+DCCP

3 SCTP

4 Ethernet

……

Describe a TML

• TML Attributes– Multicast list

multicast list = {multicast id, member1, member2, ... memberN}

where, multicast id is the PL layer multicast ID

members are FE ID/CE ID

– TML event handle• for subscribe/unsubscribe a TML event

– Working TML Type• TML media type currently in use

Describe a TML

• TML Attributes (cont’d)– TML media specific attributes

• An individual TML specification may require PL to configure some extra TML parameters specific to this TML media. If any, the TML specification shall provide detailed definitions for such attributes.

– TML implementation specific TML attributes • An individual TML implementation may require PL to configure

some TML parameters specific to this implementation. If any, the individual implementation will provide detailed definitions for such attributes.

Service Primitive Design Principles

• hide implementation details regarding TML reliability, security, multicast, congestion control, etc from PL

• be decoupled from possible changes of ForCES PL layer such as the update of ForCES protocol and ForCES FE model. – More specifically, primitives should be avoided to

be coupled with ForCES protocol PDU format

TML Service Primitives

– TML Open

– TML Close

– TML Config

– TML Query

– TML Send

– TML Receive

TML Open

Result = TMLopen( )

Result:

the returned result; it shall indicate whether the TML open is succeeded or not.

if succeeded, a 'TML id' returned

if not, an error code may be returned to indicate the error type

TML Close

Result = TMLclose (

TML id

)

TML Config

Result = TMLconfig ( TML id, operation type, TML attribute id, TML attribute data [,optional parameters] )

possible operation type: SET, DELETE, MODIFY

TML Query

Result = TMLquery (

TML id,

TML attribute id or TML capability id,

[,optional parameters]

)

TML Send

Result = TMLsend (

TML id,

message destination id,

message type,

message priority,

message length,

message PDU

[, timeout]

[, more optional parameters]

)

TML Receive

Result = TMLreceive (

TML id,

message length,

message PDU,

timeout,

[, optional parameters]

)

Operation Notes

• CE to FEs Multicast1. CE forms a multicast list with a multicast id and FE IDs as the

members (may also include the CE ID itself).

2. CE sends the list to the CE TML by TMLconfig service primitive

3. CE sends the list to individual FEs by CE PL Configure messages– actually to configure the attributes of FE protocol LFBs

4. FEs sends the multicast list to their TMLs by use of TMLconfig

5. In the same way as 1 to 4, CE may configure some media specific parameters for the multicast to the CE-TML and the FE-TMLs.

– with above steps, usually a PL level multicast platform can be constructed between a CE and multiple FEs.

Open Issues to be Solved

• XML definitions of FE Protocol Object or FE Object should be updated to reflect FE TML related information, because– FE TML error should be reported to CE

– FE TML congestion alert should be reported to CE

• FEPO or FEO?– If FEPO, protocol document should include it

– If FEO, FE model document should include it.

Open Issues to be Solved (cont’d)

• The text (also in the protocol document) as "A ForCES PL implementation must be portable across all TMLs.”– How to understand it?– if there is any problem with the statement?

• “… It is feasible that the implementers of  TML and PL may be from different organizations.“– shall we indicate it even it may be true?

Thank You!

And special thanks to presenter!