How IPD Is Provided to a QP or an EEC

Providing the IPD to the Local QP or EEC

The IPD is provided to the local QP or EEC in the following manner:

• RC and UC. The Maximum Static Rate (aka IPD) is supplied to the local QP when executing the Modify QP verb to transition the QP from the Initialize to the RTR state. If software is enabling APM [refer to “Automatic Path Migration” on page 575 for more information] for the local and remote QP, the IPD value the local QP is to use for the alternate path is also supplied in the verb call.

• RD. The Maximum Static Rate is supplied to the local EEC when executing the Modify EEC verb to transition the EEC from the Initialize to the RTR state. If software is enabling APM for the local and remote EEC, the IPD value the local EEC is to use for the alternate path is also supplied in the verb call.

• UD. The Maximum Static Rate is supplied in each WR posted to the UD QP's SQ using the Post Send Request verb. Specifically, it is supplied in the form of the Address Handle input parameter. The Address Handle defining the path to the message's destination UD QP was created earlier using the Create Address Handle verb and the Maximum Static Rate was supplied as one of the input parameters to that verb.

• Raw IPv6 or Raw EtherType. The Maximum Static Rate is supplied as an input parameter in each WR posted to the Raw QP's SQ using the Post Send Request verb. Refer to “Raw Transport Service Types” on page 537 for a detailed description of Raw QPs.

Providing the IPD to the Remote QP or EEC

Upon Initial Connection Establishment

When using RC, UC, or RD, the local CA's CM supplies the IPD for the remote CA's QP (in the case of RC or UC) or EEC (in the case of RD) in the communications establishment REQ message. The remote CA's CM then creates the QP (in the case of RC or UC) or EEC (in the case of RD) and programs the supplied IPD value into the QP's or EEC's context when setting it up. Refer to “Communications Management” on page 1069 for a detailed description of communications establishment.

If software is enabling Automatic Path Migration for the local and remote QP or the local and remote EEC, the IPD value the remote QP or EEC is to use for the alternate path is also supplied in the REQ message.

After Connection Has Been Established

If software desires to change the IPD assigned to the remote QP or EEC after the connection has been established, it instructs the local CA's CM to send a LAP (Load Alternate Path) communications message to the remote CA's CM. Upon receipt, the remote CA's CM programs the revised alternate path information (including the new IPD value) into the remote QP or EEC.