Re: New version of ngATM

Le Vendredi 7 Février 2003 17:52, Harti Brandt a écrit :
> Hi there,
>
> I've put a new version of ngATM on my web-page:
>
>   http://www.fokus.gmd.de/research/cc/cats/employees/hartmut.brandt/ngatm

great ;-)

>
> this version contains a number of bug fixes. The biggest change is, that
> it now runs on sparc64. So I expect most byte-order and word-size related
> problems to be fixed (in fact there were almost no such problems). It is
> now possible to use PCA200 and HE155 cards in sparcs. The drivers are
> fully busdmayfied.

Why do you need to rewrite some new ATM drivers for the ngATM architecture ?

I am using the HARP's drivers and the HARP stack with the VBR, CBR and UBR in 
order to support the RFC 1483. It works very well. ;-)

Due to the lack of PCI ATM hardware, I have worked on a new ATM driver (see 
the PROATM 155 Board from Prosum). The performance is very good with UBR, CBR 
and VBR mode. We get the full line rate with the HARP stack without any 
patches. Moreover it has been tested up to 4K PVC.

The idea of ngATM sounds nice : it provides a good new driver in order to 
support the HFA 155 board. However, HARP provides already most of the ATM 
features. However the HARP stack lacks of :
   - drivers:
            + up to now there is no ADSL driver ;-(
            + there is no OC12 driver
   - features:
            + soft SAR that could be required by many ADSL drivers.
            + OAM F4 and F5 support
Before integrating a third ATM stack that has a good architecture, it seems 
better to enhance the HARP stack that is very stable for a long time (4 
years).


Could you describe the differences between ngATM and HARP ?

>
> For HARP users there is a harp pseudo-driver if_harp. This driver attaches
> to all ngATM interfaces in the system and creates a HARP physical
> interface for each ngATM interface (using the same name - the interfaces
> are in different name spaces). It is then possible to use all HARP stuff
> over these interfaces.

It is a nice architecture ;-)

Moreover in order to emulate an ATM link, I think that Netgraph could be used 
too to provide a virtual PIF. For example in order to emulate an ATM link 
without any ATM board, a ng_HARPDEVICE node could provide on one side a 
Netgraph hook and on the other side a HARP PIF (Physical Interface). The 
Netgraph hook could be used over a UDP socket that emulates the physical ATM 
link.

       +-------+
        HARP PIF
       +---=---+
           |
  ---------=---------
     ng_HARPDEVICE
    |   |   |   |
    V   V   V   V
  VC1          VCn
  ---------=---------
           |
           V
  ---------=---------
     ng_ksocket
  ---------=---------
           |
           V
       UDP or TCP

>
> In the not so far future this allows us to converge between the different
> ATM driver types in the system. An ngATM driver can be used with HARP,
> NATM and ngATM, even at the same time (well using both ngATM and HARP
> signalling requires the use of different signalling VCIs).

Then what are the differences between your PCA200 driver and the HARP's one ?

Regards,
  Vincent

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