headers
Mania | 1 Dec 2004 15:34

PPPoE - VJ compression support.

Hi All,

Most of the freeware PPPoE clients do not seem to support VJ compression on
the PPPoE sessions and it looks like VJ compression is not supported on
PPPoE
sessions.  I am not able to locate any references in the standard RFC
mentioning about VJ compression on PPPoE sessions.  I understand that VJ is
primarily used  for PPP over HDLC (slow-speed links)/ISDN links.

Could anyone clarify whether VJ compression needs to supported on PPPoE
sessions or not ?

Thanks in advance
Mani.

***************************************************************************
This message is proprietary to Future Software Limited (FSL)
and is intended solely for the use of the individual to whom it
is addressed. It may contain  privileged or confidential information
and should not be circulated or used for any purpose other than for
what it is intended.

If you have received this message in error, please notify the
originator immediately. If you are not the intended recipient,
you are notified that you are strictly prohibited from using,
copying, altering, or disclosing the contents of this message.
FSL accepts no responsibility for loss or damage arising from
the use of the information transmitted by this email including
damage from virus.
***************************************************************************
(Continue reading)

Permalink | Reply | 2 comments |
headers
Jonathan Goodchild | 1 Dec 2004 18:55
Picon

RE: PPPoE - VJ compression support.

> Could anyone clarify whether VJ compression needs to supported on
PPPoE sessions or not ?

VJ compression doesn't work too well when packets can get discarded
silently, and that may well be the situation with PPPoE, so perhaps that
explains why the freeware implementations don't support it.

In any case, I don't believe VJ compression should have to be supported
by any particular PPP implementation - it is after all an option which
can be rejected.

Jonathan Goodchild

_______________________________________________
Pppext mailing list
Pppext <at> ietf.org
https://www1.ietf.org/mailman/listinfo/pppext
Permalink | Reply | 0 comments |
headers
Carsten Bormann | 1 Dec 2004 21:31
Favicon
Gravatar

Re: PPPoE - VJ compression support.


On Dec 01 2004, at 15:34 Uhr, Mania wrote:

> Hi All,
>
> Most of the freeware PPPoE clients do not seem to support VJ 
> compression on
> the PPPoE sessions and it looks like VJ compression is not supported on
> PPPoE
> sessions.  I am not able to locate any references in the standard RFC
> mentioning about VJ compression on PPPoE sessions.  I understand that 
> VJ is
> primarily used  for PPP over HDLC (slow-speed links)/ISDN links.
>
> Could anyone clarify whether VJ compression needs to supported on PPPoE
> sessions or not ?

It certainly does not need to be (as has already been answered).

VJ compression also is a poor match to today's TCPs.
With options such as SACK and timestamps prevalent, RFC 1144 simply 
does not work any longer.

The IETF ROHC working group is in the process of finishing a new TCP 
header compression scheme that will work with current TCPs and also 
anticipates innovations like ECN.

Gruesse, Carsten

_______________________________________________
(Continue reading)

Permalink | Reply | 1 comment |
headers
Anandavel P | 14 Dec 2004 13:36

PPPoE compression/encapsulation


I have a query regarding PPPoE using Compression & encapsulation.

The compression and encription protocols often require the packets to be
delivered in sequence. In an IP network( over which a PPPoE session is
estabished ), packets could get delivered out of sequence. So how
does compression/encription work?

Is there anything i am missing?

Regards,
Anand.

-----------------------------------------------------------------------
Anandavel P.                        Tel: + 91 80 25355501 Extn: 4065
Project Leader,                     Fax: + 91 80 25351133
DSL Group, Products Division,       Email: anandvel <at> sasken.com
139/25, Ring Road, Domlur           URL: www.sasken.com
Bangalore - 560071 India.
-----------------------------------------------------------------------

"SASKEN RATED THE BEST EMPLOYER IN THE COUNTRY by the BUSINESS TODAY Mercer Survey 2004"

                           SASKEN BUSINESS DISCLAIMER
This message may contain confidential, proprietary or legally Privileged information. In case you are
not the original intended Recipient of the message, you must not, directly or indirectly, use, Disclose,
distribute, print, or copy any part of this message and you are requested to delete it and inform the
sender. Any views expressed in this message are those of the individual sender unless otherwise stated.
Nothing contained in this message shall be construed as an offer or acceptance of any offer by Sasken
Communication Technologies Limited ("Sasken") unless sent with that express intent and with due
(Continue reading)

Permalink | Reply | 1 comment |
headers
James Carlson | 14 Dec 2004 15:59
Picon

Re: PPPoE compression/encapsulation

Anandavel P writes:
> I have a query regarding PPPoE using Compression & encapsulation.
> 
> The compression and encription protocols often require the packets to be
> delivered in sequence.

Right.

> In an IP network( over which a PPPoE session is
> estabished ),

PPPoE runs over Ethernet, not IP.  Ethernet guarantees sequencing.

> packets could get delivered out of sequence. So how
> does compression/encription work?

Most of the algorithms involved either have their own sequence numbers
or have some mechanism for detecting a loss of sender/receiver
synchronization.  Even if there's reordering and loss, those
algorithms can generally deal with it.  (Though, of course, with a
performance penalty.)

> Is there anything i am missing?

Just that PPPoE doesn't run over IP, I think.

I wouldn't recommend running compression or encryption with PPPoE, as
these tend to magnify any errors that occur, but they should work as
specified.
(Continue reading)

Permalink | Reply | 0 comments |

Gmane