VLAN support of differentiated services
View Patent ↗The two types of virtual local area networks (VLANs) may be defined: p-bits-Inferred-scheduling class VLAN (p-VLAN); and VLAN-ID-Only-Inferred-scheduling class VLANs (v-VLAN). As such, upon receipt of an Ethernet frame, the type of VLAN associated with the Ethernet frame may be determined. The type of VLAN provides the receiving node with an indication of a method of determining a scheduling class. A p-VLAN supports multiple scheduling classes. For a p-VLAN, the scheduling class and drop precedence for the received Ethernet frame may be determined based on a “service map” that describes the relationship between the p-bits and forwarding treatment. A v-VLAN supports a single scheduling class. As such, the scheduling class for a received Ethernet frame may be determined based on the VLAN-ID of the received Ethernet frame. The described VLAN QoS information may be configured or signaled across the network. Advantageously, the methods may be applied in connectionless, connection-oriented and path-oriented Ethernet networks.
1. A method of preparing a network node for forwarding data frames associated with a virtual local area network (VLAN), said method comprising:
receiving, at said network node, a first service map defining a first mapping between:
predetermined contents of a user priority field in a header of each data frame; and
selected ones of a set of frame per hop behaviors controlling a forwarding treatment of data frames by the network node; and
associating, at the network node, said first service map with a virtual local area network identification (VLAN-ID) of the virtual local area network, such that the network node forwards data frames including the VLAN-ID in accordance with the first service map.
2. The method of claim 1 wherein the first service map further comprises a second mapping between each frame per hop behavior and a frame scheduling class.
3. The method of claim 1 wherein the first service map further comprises a second mapping between each frame per hop behavior and a frame drop precedence.
4. The method of claim 1 wherein the set of frame per hop behaviors comprises any one or more of: Expedited Forwarding; Assured Forwarding; Class Selector; and Best Effort.
5. The method of claim 1 further comprising receiving, at said network node, a second service map and associating, at said network node, said second service map with another VLAN-ID, and wherein the second service map is different from the first service map.
6. The method of claim 1 further comprising:
receiving, at said network node, a bandwidth profile; and
associating, at said network node, said bandwidth profile with said (VLAN-ID), such that the network node forwards data frames including the VLAN-ID in accordance with the bandwidth profile.
7. In a network node, a method of handling a received data frame, said method comprising:
determining a contents of a virtual local area network identification (VLAN-ID) field in a header of the received data frame, the determined contents identifying a given virtual local area network;
based on the determined contents of said VLAN-ID field, selecting one of a set of previously defined service maps, each service map defining a respective mapping between:
predetermined contents of a user priority field in a respective header of each data frame; and
selected ones of a set of frame per hop behaviors controlling a forwarding treatment of data frames by the network node;
determining a value of contents of the respective user priority field in the header of the received data frame;
determining a frame per hop behavior for the received data frame, based on the selected service map and the value of contents of the respective user priority field of the received data frame; and
the network node forwarding the received data frame based on the determined frame per hop behavior.
8. The method of claim 7 wherein the received data frame is an Ethernet frame.
9. The method of claim 8 wherein the header of the received data frame includes an IEEE 802.1Q tag.
10. The method of claim 9 wherein the IEEE 802.1Q tag includes the VLAN-ID field and the user priority field.
11. The method of claim 7 wherein said given virtual local area network is connectionless.
12. The method of claim 7 wherein said given virtual local area network is connection-oriented.
13. The method of claim 7 wherein said given virtual local area network is path-oriented.
14. The method of claim 7 wherein the set of frame per hop behaviors comprises any one or more of: Expedited Forwarding; Assured Forwarding; Class Selector; and Best Effort.