Conference ozrock::x25_osf

    The following answers are independent of the card used except where
    noted.
    
> 1) Using this card, can it present both a DTE and a DCE appearance, h/w and
> s/w? What does the s/w interface look like?  
    Any port can be independently configured at both datalink and packet
    layer to act as a DTE or DCE. The s/w interface is described in the
    manuals. The manuals are on the documentation CD and at the network
    location given by an early note in the conference. See late replies to
    note 2 or 3.
    
> 2) Can I control the state machine timers?  Can the controller be 
> programmed to ACK at L3 on its own, or does it require application 
> supervision?  
    	Timers can be controlled from NCL - the network management utility.
    The X.25 software acknowledges incoming data as the data is given to
    the application; depending on window size. The details are undocumented
    because they may change.
    
> 3) Does it support basic and extended (no need for super-extended) 
> sequencing with user specified windowing for both L2 and L3?  
    	The software supports modulo-8 and modulo-128 sequencing at both L2
    and L3. The L2 and L3 settings are independent and port settings are
    independent. I don't know what "super-extended" means!
    
> 4) What frame sizes are supported?  
    Packet sizes to 4096 data octets (less for other controllers than
    PBXDP); frame sizes to over 8k (I think, see the SPD for the details).
    
> 5) How does PVC operation work (i.e., can the card present an 
> SVC appearance to an application while running PVC)?
    Any combination of SVCs and PVCs can be configured per port UP TO a
    maximum of 4096 with a global maximum of 4096 PVCs and active SVCs.
    (that is if you configure 4000 PVCs you can only have 96 SVCs active at
    any time).
    
> 6) Can I access link performance data from software and utilities? 
    Don't understand the question. NCL maintains an extensive set of
    counters at each of the physical interface layer, datalink layer and
    packet layer. Call statistics can be collected by an application.
    
> 7) What messaging rates are achievable (i.e., with L3 frames at W 
> bytes, sending X bytes of user data on two Y kbps links, full
> duplex, with non-blocking windowing, the maximum message rate is
> Z per second per link, for range limiting values of W, X and Y)?
    Depends. On an AlphaStation 400 4/266 you could probably get over 1200
    packets/sec with packet sizes of <= 128 bytes and sufficiently high
    line speed and a suitable non-demanding application. On a
    AlphaServer4100 you would probably get considerably more. The card will
    handle line speeds to over 2.2Mbps on all ports concurrently but
    whether you can saturate the line or not will depend very heavily on
    packet size.
    

The questions are specific to a customers needs and they will make
decisions based upon it.  You reference the NCL utility which means using 
the DECnet/OSI package containg X.25, is there any reason why I couldn't
utilize the WAN package in place of DECnet/OSI?   This is assuming 
utilizing the latest WAN package that supports the latest DU.

Any problems with utilizing the questions in my response to my customer?

Cheers and Thanks
Steve
[Posted by WWW Notes gateway]

I've asked the customer for more detail specific to your questions of 
reply #1.   Can you help to reply to the following, thanks in advance?

Cheers
Steve

>  Can you explain "super-extended" in more detail, since
>  I'm not familiar with that term?

ISO/IEC 7776:Jul95, X.25 LAPB, was amended in 1996 for the
"multi-selective rejection option," 3.2 and 3.3.  Option 10
was also enhanced in Amendment 1, and is now split into 10.1
(128) and 10.2 (32,768).  The latter is referred to as
"super-extended" sequencing (same as in SSCOP).  Again, we do
not need this LAPB feature, just the two moduli you do support.


>> 5) How does PVC operation work (i.e., can the card present an 
>> SVC appearance to an application while running PVC)?
>    Any combination of SVCs and PVCs can be configured per
>    port UP TO a maximum of 4096 with a global maximum of 4096
>    PVCs and active SVCs. (that is if you configure 4000 PVCs
>    you can only have 96 SVCs active at any time).
>    

In some implementations of X.25, it is possible to simulate
an SVC to the application, while actually running a PVC on
the link (one configures the DNAs for the application, and
the LCN for the PVC).  I use this feature often.  Does the
DEC X.25 package support such a feature?


[Posted by WWW Notes gateway]

> You reference the NCL utility which means using 
> the DECnet/OSI package containg X.25, is there any reason why I couldn't
> utilize the WAN package in place of DECnet/OSI?
	The WAN product includes the network management component of DECnet/OSI.
You don't ned all of DECnet to run X.25; just the network management component.

> Any problems with utilizing the questions in my response to my customer?
	No.

	Thanks for the explanation of "super extended". However I'm not sure
what help you want to reply to the explanation.