HP-UX iSCSI Software Initiator Support Guide (Edition 7)

1.5 iSCSI Login
The iSCSI login enables:
• A TCP connection for iSCSI use
• Authentication of the parties
• Negotiation of the session’s parameters
• Marking the connection as belonging to an iSCSI session
An iSCSI session is established to identify all of the connections between an initiator and a target
belonging to the same I_T nexus.
Targets listen on a well-known TCP port (3260, as defined in the iSCSI Protocol Specification), or
on a user configured TCP port, for incoming connections. The initiator begins the login process by
connecting to one of these TCP ports.
An iSCSI Session has two phases:
• Login Phase
• Full Featured Phase
Figure 6 iSCSI Session Establishment and Phases
Login Phase
The iSCSI Login Phase consists of Login requests and responses. Once authentication has occurred
and operational parameters have been set, the session transitions to the Full Feature Phase and
the initiator begins performing SCSI I/Os. NOTE: Using authentication is optional.
iSCSI parameters are negotiated using Login Requests and Responses, during session establishment.
During the Full Feature Phase, iSCSI parameters are negotiated using Text Requests and Responses.
In both cases the mechanism is an exchange of iSCSI-text-key=value pairs (also referred to as
key=value pairs).
The Login Phase proceeds in two stages:
• Security/Authentication Stage
This stage consists of text exchanges using IDs, Certificates, etc., using key=value pairs.
8 iSCSI Overview