Client-bid message flow

The following figure shows a client-bid flow, where the client attempts to connect to the server.

This flow can occur when the client has already joined the z/OS® cross-system coupling facility group and notices that a server has joined the group. The client-bid flow is:

  1. Client-Bid: MC, SD, SE
  2. ACK: MC, SD, SE
Figure 1. Client-bid flow
An arrow from the client to the server represents the first flow of the client-bid exchange, the client-bid request. A second arrow from the server to the client represents the second flow of the client-bid exchange, the ACK response.

The following table shows the contents of the OTMA message prefix in the first flow of a client-bid exchange: the client-bid request. The table shows the contents of the message control data, state data, and security data sections of the OTMA message prefix.

Table 1. Contents of the OTMA message prefix in the first client-bid flow of a client bid exchange
Message prefix section Contents of prefix section
Message control data Architecture level = 1 Message type = command Response flag = response requested Command type = client-bid Prefix flag = state data + security data
State data The state data format for command messages applies to these fields: Length Member name Originator's token Destination token (DRU exit name) MaxBlocksize Aging value Hash table size
Security data (Utoken)

The following table shows the contents of the OTMA message prefix in the second flow of a client-bid exchange: the acknowledgement. The table shows the contents of the message control data, state data, and security data sections of the OTMA message prefix.

Table 2. Contents of the OTMA message prefix in the second, acknowledgement flow of a client-bid exchange
Message prefix section Contents of prefix section
Message control data Architecture level = 1 Message type = command and response Response flag = ACK Command type = client-bid Prefix flag = state data + security data
State data The state data format for command messages applies to these fields: Length Member name Originator's token Destination token (DRU exit name) MaxBlocksize Aging value Hash table size
Security data Utoken