Cisco 6500 - Catalyst Series 10 Gigabit EN Interface Module Expansion Livre blanc - Page 2

Parcourez en ligne ou téléchargez le pdf Livre blanc pour {nom_de_la_catégorie} Cisco 6500 - Catalyst Series 10 Gigabit EN Interface Module Expansion. Cisco 6500 - Catalyst Series 10 Gigabit EN Interface Module Expansion 18 pages. Distributed forwarding card 4 for ws-x68xx, ws-x69xx, and select ws-x67xx modules
Également pour Cisco 6500 - Catalyst Series 10 Gigabit EN Interface Module Expansion : Note d'installation (14 pages), Manuel de solution (17 pages), Note d'installation (46 pages), Livre blanc (19 pages), Description (1 pages), Bulletin d'information sur les produits (6 pages), Avis (4 pages), Fiche technique (9 pages), Fiche technique (18 pages), Manuel de configuration (8 pages), Note d'installation (28 pages), Manuel de dépannage (11 pages), Note d'installation (18 pages), Manuel de l'utilisateur (17 pages), Note d'installation (24 pages), Manuel (19 pages), Note d'installation (36 pages)

Imprimer la page

Cisco 6500 - Catalyst Series 10 Gigabit EN Interface Module Expansion Livre blanc

Figure 1. CoS Field

Cisco Systems

supports the Inter-Switch Link (ISL) VLAN tagging option on selected Cisco Catalyst 6500 line cards. ISL is a Cisco proprietary

VLAN tagging option that also supports an inbuilt 3-bit CoS field just like the IEEE 802.1Q option mentioned earlier.

Type of Service

Built into every IP packet is an IP header, and like in the Ethernet example earlier, the IP header also contains a field that defines a priority value

for this packet. This field is the type-of-service (ToS) field. Unlike the CoS field, the ToS field is an 8-bit field. There are two ways to set a priority

value in the ToS field. One method, called IP precedence, uses the 3 most significant bits of the ToS field to yield eight priority values.

Differentiated Services Code Point (DSCP) is a second method for assigning a priority to an IP packet. DSCP uses the 6 most significant bits of the

ToS field to yield 64 different priority values. Figure 2 shows where the ToS bits are found in the IP header.

Figure 2. Reading IP Precedence and DSCP from the ToS Byte

Important notices, privacy statements, and trademarks of Cisco Systems, Inc. can be found on cisco.com.

Page 2 of 18