On Tuesday, 09/12/2006 at 11:53 CDT, Ron Greve <[EMAIL PROTECTED]> 
wrote:

> Since we had RSCS, VTAM  and JES working with  SCTC device/links
> we thought these links would also work with TCP/IP. (and it sounds
> like it would have if we were talking from Z/OS TCP/IP to Linux TCP/IP)
> 
> What I think I'm hearing is that VM TCP/IP only supports BCTC (Parallel
> Basic Mode CTC support over ESCON).

Not.  VM TCP/IP supports 3088/ESCON/FICON CTCAs in extended mode.  You 
must code one end of the connection as TYPE=CTC and the other end as 
TYPE=CNC.  Code UNIT=SCTC on both ends.  If you code UNIT=BCTC, then the 
attempt by TCP/IP to switch the adapter to extended mode is ignored 
(no-op) and things will go rapidly downhill.  No I/O error (i.e. Command 
Reject), but a link that doesn't operate correctly.

The above applied to z/OS and Linux, too.

> I think the ccw_chan_mode parm in SLES specifies the type of CTC
> link.  I think "0" would correspond to BCTC.
> 
> >CCW_CHAN_MODE="0"

Nope. CCW_CHAN_MODE corresponds to the specific link-layer protocol to be 
used by CTC device driver, not to the channel mode.  Code 0 for VM and 
VSE, 1 for Linux, and 3 for MVS.

Since physical connections don't have the convenient "cross-coupling" of 
even-to-odd addresses used in guests, you must instruct VM TCP/IP to write 
to the channel Linux is listening on.  Do this by coding '1' as the CTC's 
DEVICE statementin the VM TCP/IP configuration.

Alan Altmark
z/VM Development
IBM Endicott

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