Subject: Questions about Multiple connections in a session

From: Menqiu Wang <[email-masked]>
Date: Fri, 07 Dec 2001 12:44:33 -0800

Hi,
  I read the iSCSI draft 09, and I get a little bit confused about
multiple connections within a session.

 (1) As my understanding, this means that during a session, there can be
serveral TCP connections co-existing at the same time. Is this right?

(2) But how do they get connected? At the initiator side, they use
different IP addresses, and at the target side, they share the same TCP
port and use different IP addresses? If this is right, it sounds weird
because usually storage devices on the network only have one IP address.
What's relationship between iSCSI TCP port and SCSI port?

(2) What's the motivation to support multiple connection within a
session? Just for performance and reliability?

Any of your help will be really appreciated.

Thanks,
Mengqiu

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From: [email-masked]
Date: Fri, 7 Dec 2001 17:02:13 -0500

> serveral TCP connections co-existing at the same time. Is this right?

Yes.

> because usually storage devices on the network only have one IP address.

Sharing the Target TCP port and IP address is allowed.  Different IP
addresses
and TCP ports are also allowed.

> What's relationship between iSCSI TCP port and SCSI port?

For iSCSI, the SCSI port is a software entity that binds all the
TCP connections together into a single iSCSI session.  I suggest
looking at the naming and discovery draft for a longer explanation. 

> session? Just for performance and reliability?

Yes.

--David

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David L. Black, Senior Technologist
EMC Corporation, 42 South St., Hopkinton, MA  01748
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[email-masked]       Mobile: +1 (978) 394-7754
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From: "Julian Satran" <[email-masked]>
Date: Sat, 8 Dec 2001 08:41:52 +0200

Menqiu,

1 - correct
2 - connections particiapte in a "session". At login any connection that 
is not the first is created with the same session-identifier. All this is 
explained at some length in section 2 and you will find there also the 
mapping to SCSI port
3 - the motivation - "only" performance and availability

Julo

Menqiu Wang <[email-masked]>
Sent by: [email-masked]
07-12-01 22:44

        To:     [email-masked]
        cc: 
        Subject:        Questions about Multiple connections in a session

Hi,

Thanks,
Mengqiu