RE: iSCSI: Flow Control

[JoeBre@exabyte.com]

Title: RE: iSCSI: Flow Control

> -----Original Message-----
> From: David Robinson [mailto:David.Robinson@EBay.Sun.COM]
> Sent: Thursday, September 21, 2000 12:00 AM
> To: ips@ece.cmu.edu
> Subject: Re: iSCSI: Flow Control
>
...
>
> I understand the basis of RTT is in the SCSI legacy of targets
> with very small buffers where limits might be in the order of
> single digits.  With modern buffers and cheap memory I question
> its need.
>
>       -David
>

We implement a device with a buffer of 32MB. Maybe that is not a 'modern buffer' - I dunno. When a transfer exceeds that size, a RTT-like mechanism will be needed. No matter how modern the buffer is, implemented with arbitrarily cheap memory, there will be some limit that cannot be exceeded without breaking the desired transfer into multiple physical transfers, with the target informing the initiator when it can accept more data (RTT).

Joe