Product manual

VTrak E-Class Product Manual
372
Trunk
A trunk is an aggregation of two or more iSCSI ports on the same RAID
controller. Also known as a link aggregation. This feature combines ports to
increase bandwidth. Ports must be enabled to add them to a trunk. Trunks are
identified by their Trunk IDs.
When you create a trunk, you specify:
• Controller ID – RAID controller whose iSCSI ports you are using.
• Master port – Any available iSCSI port.
• Slave ports – The remaining available iSCSI ports.
Session
A session is a group of TCP connections that link an iSCSI initiator with a target.
Each RAID controller supports a maximum of 1024 sessions, or 2048 per
subsystem.
Session has one option, Keep Alive, sometimes written, “Keepalive.”
Keep alive is an HTTP protocol for maintaining an active connection between teh
iSCSI client and server. The client sends a keepalive signal is sent over the
network at predefined intervals.
• When the server replies, the client knows that the link is up (the connection
between client and server works).
• If there is no reply, the client assumes the link is down and routes future data
over another path until the original link is up again.
The keep alive feature on VTrak tells the RAID controller to reply to keep alive
signals, informing the client that its link to VTrak is up.
You can enable Keep Alive on individual sessions, or as a global setting for all
sessions.
iSNS
Internet Storage Name Service (iSNS) is a protocol that facilitates automated
discovery, management, and configuration of iSCSI devices on a TCP/IP
network. iSNS service runs on an iSNS server on your network.
You can enable iSNS on the VTrak and specify the IP address and port number
of the iSNS server.
CHAP
Challenge Handshake Authentication Protocol (CHAP) is an authentication
mechanism used to authenticate iSCSI sessions between initiators and targets.