Talk:User Datagram Protocol

message: But I corrected several things like *space**period* and "dotdot" at the end of sentences.  —Preceding unsigned comment added by 216.212.238.139 (talk) 00:51, 3 July 2008 (UTC)
replies: text: Message is used now and this seems reasonable. Packet is still used for exchange required for setup. This is correct, there are no segments until the connection is established. ~Kvng (talk) 21:37, 5 August 2021 (UTC)
thread_title:  I may just be being picky... 

message: It is clear from the RFC that User Datagram Protocol is what UDP refers to. The article mentions alternative mappings: Universal Datagram Protocol and Unreliable Datagram Protocol. Are these incorrect alternative names worth noting (and perpetuating)? --Kvng (talk) 14:29, 14 July 2010 (UTC)
replies: text: Unreliable Datagram Protocol mentioned in User_Datagram_Protocol#Attributes. Universal Datagram Protocol no longer found in article. ~Kvng (talk) 21:37, 5 August 2021 (UTC)
thread_title:  Alternate names 

message: Not sure what to do about this, but wikipedians might have some suggestions. UDP (like TCP) was in active development prior to the RFC that documented it was issued. So the 1980 date for its creation may confuse people who know the history of the Internet protocol development. In particular, the decision to split the original TCP design into three protocols was taken in 1977, three years before RFC768 froze its design. What was a purely virtual circuit model prior to that point was split into the IP layer (now IPv4) which carried host-to-host datagrams between gateways (now called routers) and two higher level protocols, UDP and TCP. This was the result of strong advocacy for support of a class of uses that could not accept the constraints imposed by reliable, exactly once, in-order delivery.
Not sure the best citation for this, but many Internet histories discuss this event. The packet formats and behavior of the three different protocols were implemented and in use soon after that at a number of sites, well before 1980.
AdScientiam (talk) 19:21, 4 December 2017 (UTC)
thread_title:  Beginnings/creation 

message: It says in the first paragraph of the lead "Prior communications are not required in order to set up communication channels or data paths." However would it not be necessary to use something like ARP to obtain a MAC address for the IP address used by UDP?
Graham.Fountain | Talk 12:22, 5 August 2021 (UTC)
replies: text: That's too pedantic to deserve discussion in the lead but could be added to the body. Maybe in User_Datagram_Protocol#Attributes. ~Kvng (talk) 21:37, 5 August 2021 (UTC)

text: No. A computer on one network can send UDP packets to a computer on another network without any prior communication. The sender forwards UDP to the nearest router which forwards it so it eventually arrives at a router on the destination network which delivers it to the destination. ARP might be needed if the computer had not recently been communicating with its router, but that does not involve end-to-end communication. Johnuniq (talk) 23:23, 5 August 2021 (UTC)
replies: text: However, if the destination is in the same subnet as the source, there are no routers involved and the source will need to have an ARP exchange directly with the destination before sending a UDP/IP packet. ~Kvng (talk) 16:32, 12 August 2021 (UTC)
replies: text: Now we're into semantics regarding what "Prior communications are not required" means. It's certainly true that UDP never requires prior communications. and it's true that the common example I mentioned involves no prior communication. The underlying packet delivery service may or may not exchange packets first. Johnuniq (talk) 00:42, 13 August 2021 (UTC)
thread_title:  Use of ARP