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Forces-IPTML Design. by Alex Audu, Jamal H. Salim, Avri Doria. <draft-audu-forces-iptml-00.txt>. ForCES FRAMEWORK. CE. ForcesPL. TML. Internal Control. External Control. Wire. Data. Wire. Data. TML. ForcesPL.
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Forces-IPTML Design by Alex Audu, Jamal H. Salim, Avri Doria <draft-audu-forces-iptml-00.txt>
ForCES FRAMEWORK CE ForcesPL TML Internal Control External Control Wire Data Wire Data TML ForcesPL Silicon API FE
TML Functions • Reliable Service to FPL • Used to transport internal control messages between CE and FE • Unreliable Service to FPL • Used to transport externally sourced control data (e.g. Hello packets) between CE and FE • Security • Authenticate FE endpoints • Authenticate messages. • Congestion Control • Unicast, Multicast and Broadcast • Stream Prioritization
Key Design Criteria • Simplicity • Easy to implement • Keep generic functions in PL layer • Statelessness • Stateless as much as possible to reduce complexity • Transparent as much as possible to CE-PL and FE-PL • Security and Anti-DOS • Provide independent data and control paths between PLs • One may be in reliable and the other in unreliable mode • Trust Model • CE-TML is the trusted node. • FE-TML has to authenticate to CE-TML
TML Overview • ULP to TML Interface • Calls out minimum service primitives TML has to provide ULP to achieve peer-to-peer ULP communication. • Primitives map to implementation specific APIs. • TML to TML Messages • Specify message interaction between peer TMLs to provide needed services to ULPs. • Message consists of common header and a payload.
ULP-to-TML Interface • Initialize – allows ULP to initialize TML layer • Join – allows FE-ULP to join a CE-TML unicast group. • Join Multicast – allows FE endpoint to join a multi-cast address group in CE-TML • Leave – allows FE-ULP to leave a CE-TML unicast group • Leave Multicast – allows an end-point to leave a multicast address group. • Shutdown – allows ULP to shut down TML gracefully • Send-Reliable – allows ULP to send data reliably to peer • Send-Unreliable – allows ULP to send data unreliably to peer. • Receive – allows ULP to get (poll) data from TML • Data-Arrive – allows TML to inform ULP of data arrival (asynch) • Link-Error – allows TML to inform ULP of various link errors • Status – allows ULP to poll TML of TML operational status
TML-to-TML Messages • Message Classes: Messages classified into 6 groups – • Management Messages (TM) • For initializing, shutdown and monitoring status • Connection Association (CA) • Establish logical connection between CE-TML and FE-TML • Security Association (SA) • For endpoint (FE-TML) authentication • Boundary Primitive Transport (BP) • Transport peer-to-peer ULP messages opaquely via TML • Asynchronous Event Handling (EH) • Report asynchronous events to ULP • Vendor Specific Extensions (VSE) • Help extend protocol beyond its current limits.
Forces-IPTML Message Structure 31 0 4 8 11 24 16 vers eType prio reserved msgClass msgType Message length Source-Address Destination Address Sequence Number Message body ( Payload)
Message Class and Messages • Connection Association • Join/Leave (request and response – unicast) • Join-MCast/Leave-MCast (request and response – multicast) • Security Association • Authenticate (request and response). • Boundary Primitives Transport • Data-Reliable/Unreliable (Request and Response). • Asynchronous Events • Error-Report, Alarm-Report, Notify • Management • Initialize, Shutdown (Request/Response), Status (request/response), Heartbeat (request/response) • Vendor Specific Extension • VS-Data (request/response)
Layers and Interfaces CE ForcesPL TML Internal Control External Control Wire Data Wire Data TML ForcesPL Silicon API FE
Layers • TML • Adapts ForCES-PL to non-IP transports (i.e. IP<-> other) • If transport is IP, we shouldn’t need TML. • Very thin layer (doesn’t do authentication or any such thing) • Makes connections with as much transparency as possible • Stateless, unless when providing reliability over un-reliable transport. • Silicon API in FE • Well defined interface for ForCES-PL to talk to FE silicon. • Needed to decouple protocol from details of FE silicon • Allows FE silicon and Forces-PL to evolve independently.
DOS Protection • Separate Control Channels • One for internally generated control data • One for externally sourced control data (e.g. hellos,..) • Created by establishing two Associations, one for each data path.
Association Phase FE CE Join Request 1 Validation of FE endpoint Join Response 2 Capability Request 3 FE Block addressing, handles and relationship Capability Response 4 Topology Request 5 Topology Response 6 PE UP 7 PE UP ack 8 State Maintenance (Element State) PE (FE) ACTIVE 9 PE ACTIVE ack 10 Data Channel Estab 11
Normal Operation FE CE Heart beat request 1 Heart beat response 2 Query Request 3 Query Response 4 Port Event Notification 5 Configure Logical Comps Req 6 Configure Logical Comps Ack 7 Control packet redirect 8