Perda de pacotes induzida por TCP sobre Referências de These UDP e Bacharel

Question

Atualmente estou escrevendo uma tese de bacharel em ciência da computação e engenharia, estamos criando um jogo de corrida em C ++ usando o OpenGL.No relatório, eu estou comparando o uso de TCP e UDP e encontrei um Fonte , que alegou que várias conexões TCP podem induzir a perda de pacotes em uma conexão UDP.Eu até tenho um bom referência

O problema reside no fato de que são 13 anos, mas não consegui encontrar nenhuma indicação de que o protocolo tenha modificado para corrigir esse problema.Eu também não consegui encontrar nenhum papel ou artigo, que sejam mais atuais, que fazem investigações semelhantes

Então, minhas perguntas são se houve alguma alteração nos protocolos que possam ser relevantes e / ou se eu deveria esquecer apenas usando essa antiga referência no relatório da tese.

Answer 1

Read the significant points in the article:

1. First, we focused on the case in which only TCP connections use all of the bandwidth of the network.
2. With the increase in the number of TCP connections, a larger number of packets can simultaneously arrive at the node, thereby making the buffer severely congested and thus making packet loss occur more often.

So the WAN link under test is saturated and the testing is for fairness of the TCP and UDP protocols. The 29 West article linked in the comments also notes:

Myth--There is no loss in networks that are operating properly.

Reality--The normal operation of TCP congestion control may cause loss due to queue overflow. See this report for more information. Loss rates of several percent were common under heavy congestion.

None of this is particularly new or should be surprising to anyone. Consider a home Internet connection, DSL or Cable with minimal speed, e.g. 2mb/s and setup one computer with Bittorrent downloading several large files, now try to run a UDP game such as Valve's Team Fortress 2. It's not going to work well.

With VoIP many networking persons started looking at methods to improve this situation which brings QoS to the table. QoS however demands co-operation both ends of the WAN and so this is of no benefit to the majority of end users. The only real solution is bandwidth throttling. If you have a 2mb link you set the TCP traffic to say 1.5mb and leave the remainder for UDP traffic for gaming.

If you are developing a split protocol game you would define a upper bandwidth limit, say 25KB/s per client for the total traffic and then define separate limits for TCP and UDP traffic within that limit, e.g. 15KB/s for TCP and 10KB/s for UDP. Generally games tend to use HTTP (TCP) for downloading game content outside of the game and then switch to UDP inside the game to remove the issue completely.