Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Quality of Service in the Internet Current strategy,implemented into each router: the best effort,or minimal service every packets are processed in the same way, - therefore it is not possible to assure a QoS for each paquet of the same application it is a brake for the deployment of such applications 。 However... the TOS (Type Of Service)field is present in IP since a long time. In sept.81,in le RFC 791,J.Postel wrote:the TOS provides an indication of the abstract parameters of the QoS desired. The TOS field has never really been exploited. 2616009:Network Traffic Engineering 1:Overview Page.11
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.11 Quality of Service in the Internet • Current strategy, implemented into each router: the best effort, or minimal service - every packets are processed in the same way, - therefore it is not possible to assure a QoS for each paquet of the same application - it is a brake for the deployment of such applications • However… – the TOS (Type Of Service) field is present in IP since a long time. – In sept. 81, in le RFC 791, J. Postel wrote: the TOS provides an indication of the abstract parameters of the QoS desired. – The TOS field has never really been exploited
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Quality of Service in the Internet ·What can we do? 2 models can be drawn: Intserv(Integrated services):data flows among applications,with flow recording at each router DiffServ(Differenciated services):flow aggregate packet tagging Any more---better solution??? 2616009:Network Traffic Engineering 1:Overview Page.12
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.12 Quality of Service in the Internet • What can we do? 2 models can be drawn: - Intserv (Integrated services): data flows among applications, with flow recording at each router - DiffServ (Differenciated services): flow aggregate + packet tagging • Any more --- better solution???
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Putting on Weight email W phone.. SMTP HTTP RTP... TCP UDP... IP+mcast +Q0S+. ethernet PPP... requires more 。 functionality CSMA async sonet.. from copper fiber radio... underlying networks 2616009:Network Traffic Engineering 1:Overview Page.13
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.13 email WWW phone... SMTP HTTP RTP... TCP UDP… IP + mcast + QoS +... ethernet PPP… CSMA async sonet... copper fiber radio... Putting on Weight • requires more functionality from underlying networks
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Quality of Service in the Internet Current strategy,implemented into each router: the best effort >or minimal service every packets are processed in the same way, therefore it is not possible to assure a Qos for each packet of the same application it is a brake for the deployment of many applications 2616009:Network Traffic Engineering 1:Overview Page.14
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.14 Quality of Service in the Internet • Current strategy, implemented into each router: the « best effort », or minimal service - every packets are processed in the same way, - therefore it is not possible to assure a QoS for each packet of the same application - it is a brake for the deployment of many applications
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 QoS provisioning:Basic principle QoS for networked applications nnnn uolez!l!n 2616009:Network Traffic Engineering 1:Overview Page.15
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.15 QoS provisioning: Basic principle