Chapter 7 Protocols for Qos Support 7.0 Increased demands o Need to incorporate bursty and stream traffic in TCP/IP architecture ◆ ncrease capacity Faster links, switches, routers Intelligent routing policies End-to-end flow control ◆ Multicasting o Quality of Service( Qos) capability o Transport protocol for streaming
1 Chapter 7 Protocols for QoS Support 7.0 Increased Demands Need to incorporate bursty and stream traffic in TCP/IP architecture Increase capacity ◼ Faster links, switches, routers ◼ Intelligent routing policies ◼ End-to-end flow control Multicasting Quality of Service (QoS) capability Transport protocol for streaming
71 Resource reservation Unicast Prevention as well as reaction to congestion required e Can do this by resource reservation ◆ Unicast End users agree on Qos for task and request from network May reserve resources a Routers pre-allocate resources If Qos not available, may wait or try at reduced Qos
2 7.1 Resource Reservation - Unicast Prevention as well as reaction to congestion required Can do this by resource reservation Unicast ◼ End users agree on QoS for task and request from network ◼ May reserve resources ◼ Routers pre-allocate resources ◼ If QoS not available, may wait or try at reduced QoS
7.1 Resource Reservation- Multicast o Generate vast traffic High volume application like video Lots of destinations ◆ Can reduce load Some members of group may not want current transmission ◆“ Channels” of video Some members may only be able to handle part of transmission Basic and enhanced video components of video stream o Routers can decide if they can meet demand 3
3 7.1 Resource Reservation – Multicast Generate vast traffic ◼ High volume application like video ◼ Lots of destinations Can reduce load ◼ Some members of group may not want current transmission “Channels” of video ◼ Some members may only be able to handle part of transmission Basic and enhanced video components of video stream Routers can decide if they can meet demand
Resource reservation problems on an internet Reservations must follow chan o Must interact with dynamic routin langes in route o Soft state-a set of state information at a router that expires unless refreshed End users periodically renew resource requests
4 Resource Reservation Problems on an Internet Must interact with dynamic routing ◼ Reservations must follow changes in route Soft state – a set of state information at a router that expires unless refreshed ◼ End users periodically renew resource requests
7.1.1 Resource Reser Vation Protocol (RSVP) Design Goals o Enable receivers to make reservations Different reservations among members of same multicast group a allowed o Deal gracefully with changes in group membership Dynamic reservations, separate for each member of group o Aggregate for group should reflect resources needed Take into account common path to different members of group o Receivers can select one of multiple sources(channel selection) o Deal gracefully with changes in routes Re-establish reservations o Control protocol overhead o Independent of routing protocol 5
5 7.1.1 Resource ReSerVation Protocol (RSVP) Design Goals Enable receivers to make reservations ◼ Different reservations among members of same multicast group allowed Deal gracefully with changes in group membership ◼ Dynamic reservations, separate for each member of group Aggregate for group should reflect resources needed ◼ Take into account common path to different members of group Receivers can select one of multiple sources (channel selection) Deal gracefully with changes in routes ◼ Re-establish reservations Control protocol overhead Independent of routing protocol