North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: PPP Question
Catching up on NANOG after returning from IETF, I found this incongruous message, and would like to correct the misinformation. The PPP Maximum Receive Unit is negotiated, but this is a "maximum", not a "fixed" size. Smaller packets can be sent. While it would be perfectly legal to fill the remainder of the packet with padding, I know of no vendor that does it. This would seriously waste bandwidth. The padding feature is available for old chipsets that require 16-bit and 32-bit output data alignment. Further questions about PPP should be sent to the [email protected] mailing list, as designated in RFC1661.... Yes, NANOG is also hosted by Merit, but the lists have different purposes. Really. As usual, joining a list requires a message to <list>-request. I was amazed at the number of messages arising from nanog list members complaining that [email protected] did not allow sending a "join", "request", "subscribe" or other subject to the mailing list directly. (heavy sigh) > From: "Chris MacFarlane" <[email protected]> > More to the point is that the frame size is negotiated while handshaking. > Once two devices agree on the size it is fixed for the duration of the > session. > > -----Original Message----- > From: George Janosik <[email protected]> > >Is a PPP frame size static or elastic? RFC 1661 states: > >... > >But, it also says the the Information field "MAY" be padded up to the MRU. > > > >I have hard time believing that a PPP frame would be static. [email protected] Key fingerprint = 17 40 5E 67 15 6F 31 26 DD 0D B9 9B 6A 15 2C 32
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