From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc297.txt | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 doc/rfc/rfc297.txt (limited to 'doc/rfc/rfc297.txt') diff --git a/doc/rfc/rfc297.txt b/doc/rfc/rfc297.txt new file mode 100644 index 0000000..ff9cb68 --- /dev/null +++ b/doc/rfc/rfc297.txt @@ -0,0 +1,112 @@ + + + + + + +NETWORK WORKING GROUP Dave Walden +REQUEST COMMENTS #297 BBN +NIC #8485 1/31/72 +Categories: C or maybe D +Updates: none +Obsoletes: none + + TIP Message Buffers + + We have recently heard some groaning about the size of the TIP's +message buffers. While we realize these aren't as big as some Hosts +might desire, they aren't as small as the intensity of the groans +suggest either. + + Let's first consider messages going from a TIP to another Host. +The buffers have the following sizes: + + device numbers buffer size (in 8 bit characters) + 1-2 64 + 3-16 32 + 17-41 16 + 42-62 8 + 63 6 + +The TIP user has the option of having his messages sent 1) every +character, 2) on line feeds and/or com's, 3) every nth character, or +4) the OR of 2) and 3). Selecting to have messages sent every large +number of characters, say 100, will result in the TIP sending the +longest messages it can for a given device. Hosts which don't like to +receive very short messages might advise users accessing them from a +TIP to set the TIP's parameters to use the maximum length buffer. + + Now let's consider messages going from another Host to a TIP. +The buffers have the following sizes: + + device numbers buffer size (in 8 bit characters) + 1 96 + 2 64 + 3 48 + 4-17 24 + 18-35 16 + 36-63 8 + + + + + + + + + + [Page 1] + +The TIP double buffers its terminal output. Thus, when a TIP terminal +makes a connection to a Host, the TIP sends off an allocation of +between 8 and 96 characters, depending on the terminals device number, +and when a message comes using up the allocation, the TIP immediately +sends another allocation for the same number of characters while it +prints the first buffer. + + For traffic both to and from the TIP, lower numbered devices have +bigger buffers. Therefore, users of line oriented systems, as well as +users of higher speed devices, should try to come in through the lower +numbered ports on the TIP's multi-line controller, if possible. + + The sizes of the TIP's message buffers and the number of each +size are not permanently fixed and can be changed if a better +distribution is suggested. We didn't know what size buffers to +provide so we have provided a variety, What is fairly fixed is the +total amount of buffer space: two output buffers and one input buffer +for each of 63 devices must come out of this total buffer space. + + The answer to your question "Why not dynamically allocate buffers +at run time?" is: It is a complicated job to do that. It requires +memory compactions, a mechanism to reclaim space from current users +when a new user comes on, etc. Our guess is that the code to +dynamically allocate buffers at run time would reduce the total space +available for buffers by about one-fifth. + + + + + [ This RFC was put into machine readable form for entry ] + [ into the online RFC archives by BBN Corp. under the ] + [ direction of Alex McKenzie. 12/96 ] + + + + + + + + + + + + + + + + + + + + [Page 2] + -- cgit v1.2.3