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Network Working Group                                 Chuck S. Kline CSKRequest for Comments: 460                                           UCLANIC 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.Kline                                                           [Page 1]

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.   5 General Information      5a Host Name: ----      5b Site Number: ----      5c Your name ----      5d Main cpu is a ---- (360/75, PDP-10, B6700, etc.)      5e Operating system in main cpu is ---- (tenex, os/360, etc.)      5f Is documentation available on your NCP?         5f1 user level (how to use NCP)         5f2 system level (implementation)         5f3 Is the documentation available at the NIC?   6 Imp interface      6a built:         6a1 in house         6a2 contracted to ----      6b full or half duplex?      6c maximum bandwidth is ---- baud in each direction   7 Coding of NCP      7a ncp was written:         7a1 in house            7a1a written in ---- man-months            7a1b Name of person who wrote NCP ----Kline                                                           [Page 2]

RFC 460                        NCP Survey                  February 1973            7a1c debugged in ---- man-weeks            7a1d machine hours used in development and debugging of NCP            ----         7a2 contracted to ----            7a2a contractor took ---- man-months         7a3 supplied another site without modification by this site         (specify site where NCP obtained from ------).         7a4 supplied from another site but modified by this site for         different system or for other reasons (specify site where NCP         obtained from ------)            7a4a modifications took ---- man-weeks      7b NCP is maintained:         7b1 in house (person's name ----)         7b2 by another site (specify site ----)      7c Size of NCP code:         7c1 Total size of all NCP code (not tables or buffers) as         described above            7c1a ---- words of ---- bits per word         7c2 size of code which initializes NCP (on system up or after         NCP or NET crash)            7c2a ---- words of ---- bits per word         7c3 size of code which handles opening and closing of         connections            7c3a ---- words of ---- bits per word         7c4 size of code which moves data from user process to Imp         handler or from Imp handler to user process            7c4a ---- words of ---- bits per wordKline                                                           [Page 3]

RFC 460                        NCP Survey                  February 1973         7c5 size of Imp handler code            7c5a ---- words of ---- bits per word         7c6 size of other code (explain what it is)            7c6a ---- words of ---- bits per word      7d Size of NCP tables:         7d1 size of tables indexed by open connection (i.e. tables for         control of open connections)            7d1a ---- entries or ---- words per entry of ---- bits per            word         7d2 size of tables indexed by link (i.e. tables for link         management and for quick association of an input message with a         process)            7d2a ---- entries of ---- words per entry of ---- bits per            word         7d3 size of other tables (explain)            7d3a ---- entries of ---- words per entry of ---- bits per            word   8 Host-Imp communications      8a Imp handling is performed in         8a1 main cpu         8a2 additional processor (specify machine ----)      8b Imp handling is performed at:         8b1 interrupt level by resident code         8b2 scheduled process with resident code         8b3 scheduled process with swappable code      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)Kline                                                           [Page 4]

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   9 NCP-Imp handler communications      9a NCP communicates with Imp handler by         9a1 putting message on queue for handler and waking         (unblocking) handler (i.e. shared memory approach)         9a2 some other mechanism (explain)   10 NCP-User communication      10a Mechanism:         10a1 special mechanism for network (i.e. different than files)         using:            10a1a shared resident memory            10a1b shared non-resident (swappable memory or file)            10a1c other (explain)         10a2 similar to file io but network assigned rather than file         (i.e. transparent to user process coding)      10b Bytes sizes allowed (circle all)         10b1 1 bit         10b2 7 bit         10b3 8 bit         10b4 9 bit         10b5 16 bit         10b6 18 bit         10b7 24 bit         10b8 32 bitKline                                                           [Page 5]

RFC 460                        NCP Survey                  February 1973         10b9 36 bit         10b10 other (explain)   11 Buffer space allocations      11a initial allocation when connection (receive) is opened         11a1 ---- messages and ---- bits      11b factors which will change this allocation         11b1 up         11b2 down      11c conditions which would cause a giveback command to be sent   12 Protocol facilities      12a Errors         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 measurementKline                                                           [Page 6]

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?   13 Time outs      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)   16 Other Comments      16a Please feel free to add other comments on your NCP which you      feel would be of interest to the network community.       [ This RFC was put into machine readable form for entry ]         [ into the online RFC archives by Grant Bowman 11/97 ]Kline                                                           [Page 7]