RFC 2823 (rfc2823) - Page 2 of 28
PPP over Simple Data Link (SDL) using SONET/SDH with ATM-like framing
Alternative Format: Original Text Document
RFC 2823 PPP SDL on SONET/SDH May 2000
SDL is defined over other media types and for other data link
protocols, but this specification covers only the use of PPP over SDL
on SONET/SDH.
The use of SDL requires the presentation of packet length information
in the SDL header. Thus, hardware implementing SDL must have access
to the packet length when generating the header, and where a router's
input link does not have this information (that is, for non-SDL input
links), the router may be required to buffer the entire packet before
transmission. "Worm-hole" routing is thus at least problematic with
SDL, unless the input links are also SDL. This, however, does not
appear to be a great disadvantage on modern routers due to the
general requirement of length information in other parts of the
system, notably in queuing and congestion control strategies such as
Weighted Fair Queuing [7] and Random Early Detect [8].
This document is not a replacement for the existing HDLC-like framing
mandated by RFC 2615 [3]. Instead, the authors intend to gain
implementation experience with this technique for operational and
performance evaluation purposes, and would like to hear from others
either considering or using the protocol as described in this
document. Please see Section 14 of this document for contact
information.
Carlson, et al. Experimental