Network Working Group Chuck S. Kline CSK Request for Comments: 460 UCLA NIC 14415 13 February 73
NCP Survey
1 This RFC is the first in a series which will request information on implementation of host to host protocol. We would appreciate a reply to this RFC from all sites within two weeks. One convenient way to reply is to make a copy of this RFC at the NIC and insert the replies at the appropriate spots. The results of this survey will be published. Please send replies to nic ident CSK or to
Charles Kline Boelter Hall 3804 UCLA 405 Hilgard Ave. Los Angeles, Cal. 90034
2 This particular RFC will deal with implementations of Network Control Programs (NCPs). Future RFCs will deal with . implementations of Telnet, RJE, etc.
3 In order to ask questions about NCPs and get meaningful replies, I will here describe what I consider to be my concept of an NCP.
3a An NCP is that part of the system which performs the tasks necessary for host to host protocol as specified by document NIC 7104 (protocols notebook).
3b NCPs contain the following parts (though not necessarily as separate pieces):
3b1 Code which handles connection establishment including maintenance of the rendezvous table (table of open and pending connections).
3b2 Code which handles transmission over open connections including buffer management and the sending of allocate and giveback commands.
3b3 Code which handles the actual movement of messages in and out of the Imp (sometimes called the Imp handler and sometimes in a separate cpu).
3b4 Other code including measurements, initialization, etc.
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RFC 460 NCP Survey February 1973
4. Please answer the following questions. It is probably appropriate to give this survey to the coder of the NCP or other knowledgeable person. Write na (not applicable) where it is appropriate. Circle the number of the appropriate choice when a choice is required. Thank you.
8c Number and size of buffers for the Imp handler (on input, number of buffers for messages before cpu will stop taking bits from imp. On output, number of buffers which may be queued before user processes will be blocked waiting for a free buffer)
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RFC 460 NCP Survey February 1973
8c1 ---- output buffers for sending to net of ---- words of ---- bits per word
8c2 ---- input buffers for receiving from net of ---- words of ---- bits per word
12a1 Do you send error commands when you detect protocol errors?
12a2 Do you log it (or take some other action) when you recieve error commands?
12b Queuing
12b1 do you allow queuing of connections (i.e. when an rts or str is received for which no request is pending, do you refuse it (send back a cls) or queue it? also do you queue when two or more requests match the same socket?)
12b1a yes always
12b1b no always
12b1c yes for listens
12b1d other (explain)
12c Are there hooks (code) in the NCP for:
12c1 NCP measurement
12c2 Network measurement
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RFC 460 NCP Survey February 1973
12c3 MSP and other protocol experiments
12c4 Do any of these hooks allow a user process to send a message with a given leader or look at all messages which arrive with a given leader?
13a How long will the NCP hold a request for connection (INIT or LISTEN) from a user process before timing out if not matched by an RTS or STR from the net ----
13b How long will the NCP hold an STR or RTS recieved from the net before timing out and sending a CLS ----
13c How long will the NCP wait after sending a reset or echo command before declaring the host dead (assuming you got a RFNM at least) ----
13d Any other timeouts? (explain)
14 Have you made any measurements on the effect of network use on your system?
14a effect of local users using telnet to go out to net
14b effect of foreign users using your system via net
14c bandwidth you have been able to achieve
15 Are any changes planned or in progress in the design or coding of your NCP? (explain)