Re[2]: PPP over IPSec (without L2TP)?

Jim Tiller <tiller_j@ins.com> Thu, 14 October 1999 18:44 UTC

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Date: Thu, 14 Oct 1999 12:53:57 -0400
From: Jim Tiller <tiller_j@ins.com>
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To: "Shriver, John" <john.shriver@intel.com>
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Subject: Re[2]: PPP over IPSec (without L2TP)?
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Hello John,

Shriver> L2TP provides the prevention of packet reordering that is REQUIRED by PPP.
Shriver> The PPP protocol assumes that packets under it will never be reordered.  PPP
Shriver> would not work directly on top of IPSec, since IPSec does not offer a
Shriver> service with any assurance of packet ordering.

Excuse my ignorance, but doesn't IPSec and IP handle this in
layer three and four? I'm personally torn on the use of L2TP
over IPSec, I see certain implementations that can benefit,
but the reasons MS gives do not impress me.
Any comments are welcome.

AtDhVaAnNkCsE
Best regards,
Jim Tiller, CISSP, MCSE+I, CCDA
james_tiller@ins.com
Network Security Consultant, INS
Tampa, Florida

"Faber est suae quisque fortunae." 
        - Appius Claudius Caecus


Thursday, October 14, 1999, 8:33:51 AM, you wrote:

Shriver> L2TP provides the prevention of packet reordering that is REQUIRED by PPP.
Shriver> The PPP protocol assumes that packets under it will never be reordered.  PPP
Shriver> would not work directly on top of IPSec, since IPSec does not offer a
Shriver> service with any assurance of packet ordering.

Shriver> The optional flow control for L2TP can also be used wisely to provide better
Shriver> performance (lower packet loss).

Shriver> Also, on Windows Dial-Up Networking, it provides a comfortable user model.
Shriver> This is not to be taken lightly.