DiffServ uses a 6-bit differentiated services code point (DSCP) in the 6-bit differentiated services field (DS field) in the IP header for packet classification purposes. The DS field, together with the ECN field, replaces the outdated IPv4 TOS field.

It is now called the "DS" (Differentiated Services, "DiffServ") field and the upper 6 bits contain a value called the "DSCP" (Differentiated Services Code Point). The upper 3 bits of DS maintains compatibility with IP Precedence.

Sep 5, 2024 · This document describes how to set the Differentiated Services Code Point (DSCP) values in Quality of Service (QoS) configurations on a Cisco router.

Explicit Congestion Notification (ECN) is an extension to the Internet Protocol and to the Transmission Control Protocol and is defined in RFC 3168 (2001). ECN allows end-to-end notification of network congestion without dropping packets.

Nov 15, 2024 · The Differentiated Services (Diffserv) architecture specifies use of the DS field in the IPv4 and IPv6 packet headers to carry one of 64 distict differentiated services field codepoint (DSCP) values.

显式拥塞通知 Explicit Congestion Notification (ECN)是 TCP/IP协议 的扩展，在 RFC 3168 (2001) 中进行了定义。 ECN支持端到端的网络拥塞通知。 通常情况下，当网络中出现拥塞的时候，TCP/IP会主动丢弃数据包。 源端检测到丢包后，就会减小拥塞窗口，降低传输速率。 但如果端到端能成功协商ECN的话，支持ECN的路由器就可以发生拥塞时在IP报头中设置一个标记，发出即将发生拥塞的信号，而不是直接丢弃数据包。 ECN减少了TCP的丢包数量，通过避免重传， …

Differentiated Services Code Point (DSCP) The Internetwork Protocol (IP) RFC791 has defined a best effort network layer service for connecting computers to form a computer network. This original specification defined an IP header field, known as the "Type of Service" (ToS).

DS 字段中的数字称为 区分服务代码点 (DSCP) 。 Codepoint (“代码点”)指的是预定义的具有特定含义的位。 在通常情况下，如果数据报拥有一个分配的 DSCP ，它在通过网络基础设施交付过程中会保持不变。 但是，某些策略可能导致一个数据报中的 DSCP 在交付过程中改变。 当通过一台具有内部排队流量的路由器时，首部中的 2 位 ECN 位用于为数据报标记拥塞标识符。 一台持续拥塞的具有 ECN 感知能力的路由器在转发分组时会设置这两位。 这种功能的设计思路是，当一个 …

This document obsoletes RFC 2481, "A Proposal to add Explicit Congestion Notification (ECN) to IP", which defined ECN as an Experimental Protocol for the Internet Community. The rest of this section describes the relationship between this document and its predecessor.

Oct 11, 2023 · Differentiated Services (DiffServ) is defined as a class of service (COS) model that is used to describe and control the IP network traffic by class. The main aim of differentiated services is to give priority to the specific traffic that needs an uninterrupted flow of data.