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diff --git a/docs/design/index.rst b/docs/design/index.rst deleted file mode 100644 index bc371e3..0000000 --- a/docs/design/index.rst +++ /dev/null @@ -1,13 +0,0 @@ -.. This work is licensed under a Creative Commons Attribution 4.0 International License. -.. http://creativecommons.org/licenses/by/4.0 -.. Copyright (c) 2016 Open Platform for NFV Project, Inc. and its contributors - -============ -OVSNFV Specs -============ - -.. toctree:: - :numbered: - :maxdepth: 3 - - specs/High-Priority-Traffic-Path.rst diff --git a/docs/design/specs/High-Priority-Traffic-Path.rst b/docs/design/specs/High-Priority-Traffic-Path.rst deleted file mode 100644 index f330a9d..0000000 --- a/docs/design/specs/High-Priority-Traffic-Path.rst +++ /dev/null @@ -1,257 +0,0 @@ -.. This work is licensed under a Creative Commons Attribution 4.0 International License. -.. http://creativecommons.org/licenses/by/4.0 - -========================================== -High Priority Traffic Path -========================================== - -https://wiki.opnfv.org/display/ovsnfv/OVSFV+Requirement+-+High+Priority+Traffic+Path - -Problem description -=================== - -A network design may need to adequately accommodate multiple classes of traffic, each -class requiring different levels of service in critical network elements. - -As a concrete example, a network element managed by a service provider may be -handling voice and elastic data traffic. Voice traffic requires that the end-to-end -latency and jitter is bounded to some numerical limit (in msec) accuracy in order to ensure -sufficient quality-of-service (QoS) for the participants in the voice call. -Elastic data traffic does not impose the same demanding requirements on the network -(there will be essentially no requirement on jitter. For example, when downloading a -large file across the Internet, although the bandwidth requirements may be high there -is usually no requirement that the file arrives within a bounded time interval. - -Depending on the scheduling algorithms running on the network element, -frames belonging to the data traffic may get transmitted before frames -belonging to the voice traffic introducing unwanted latency or jitter. -Therefore, in order to ensure deterministic latency and jitter characteristics -end-to-end, each network element through which the voice traffic traverses -must ensure that voice traffic is handled deterministically. - -Hardware switches have typically been designed to ensure certain classes -of traffic can be scheduled ahead of other classes and are also -over-provisioned which further ensures deterministic behavior when -handling high priority traffic. However, software switches (which includes -virtual switches such as Open vSwitch) may require modification in order -to achieve this deterministic behavior. - -Use Cases ---------- - -1. Program classes of service - -The End User specifies a number of classes of service. Each class of service -will be represented by the value of a particular field in a frame. The class -of service determines the priority treatment which flows in the class will -receive, while maintaining a relative level of priority for other classes and -a default level of treatment for the lowest priority class of service. As -such, each class of service will be associated with a priority. The End User -will associate classes of service and priorities to ingress ports with the -expectation that frames that arrive on these ingress ports will get -scheduled following the specified priorities. - -Note: Priority treatment of the classes of service cannot cause any one of -the classes (even the default class) from being transferred at all. In other -words, a strict priority treatment would likely not be successful for serving -all classes eventually, and this is a key consideration. - -2. Forward high priority network traffic - -A remote network element sends traffic to Open vSwitch. The remote network -element, indicates the class of service to which this flow of traffic belongs -to by modifying a pre-determined but arbitrary field in the frame as specified -in Use Case 1. Some examples include the Differentiated Services Code Point -(DSCP) in an IP packet or the Priority Code Point (PCP) in an Ethernet frame. -The relative priority treatment that frames get processed by Open vSwitch can be guaranteed by the -values populated in these fields when the fields are different. If the fields -are the same, ordering is not deterministic. - -For example: Packet A is sent with a DSCP value of 0 and packet B is sent -with a value of 46; 0 has a lower priority than 46. Packet A arrives -before packet B. If Open vSwitch has been configured as such, Packet -B will be transmitted before Packet A. - -Proposed change -=============== - -TBD - -Alternatives ------------- - -TBD - -OVSDB schema impact -------------------- - -TBD - -User interface impact ---------------------- - -TBD - -Security impact ---------------- - -TBD - -Other end user impact ---------------------- - -TBD - -Performance Impact ------------------- - -TBD - -Other deployer impact ---------------------- - -TBD - -Developer impact ----------------- - -TBD - -Implementation -============== - -Assignee(s) ------------ - -Who is leading the writing of the code? Or is this a blueprint where you're -throwing it out there to see who picks it up? - -If more than one person is working on the implementation, please designate the -primary author and contact. - -Primary assignee: - <email address> - -Other contributors: - <email address> - -Work Items ----------- - -TBD - -Dependencies -============ - -TBD - -Testing -======= - -In order to test how effectively the virtual switch handles high priority traffic -types, the following scheme is suggested.:: - - +---------------------------+ Ingress Traffic Parameters - | | +-------------------------------------------+ - | | - | | Packet Size: The size of the Ethernet frames - | | - | | Tmax: RFC2544 Max. Throughput for traffic of - | PHY0 <-------+ "Packet Size" - | | - | | Total Offered Rate: The offered rate of both - | | traffic classes combined expressed as a % of - | | Tmax - | | - | | Ingress Rates are expressed as a percentage - | | of Total Offered Rate. - | | - | | Class A: - | OVS | Ethernet PCP = 0 (Background) - | (BR0) | Ingress Rate : rate_ingress_a(n) Mfps - | | - | | Class B: - | | Ethernet PCP = 7 (Highest) - | | Ingress Rate : rate_ingress_b(n) Mfps - | | - | | Egress Traffic Measurements - | | +-------------------------------------------+ - | | Class A: - | | Egress Throughput : rate_egress_a(n) Mfps - | | Egress Latency : max_lat_egrees_a(n) ms - | | Egress Jitter : max_jit_egress_a(n) ms - | PHY1 +-------> - | | Class B: - | | Egress Throughput : rate_egress_b(n) Mfps - | | Egress Latency : max_lat_egrees_b(n) ms - +---------------------------+ Egress Jitter : max_jit_egress_b(n) ms - - -Open vSwitch is configured to forward traffic between two ports agnostic to the -traffic type. For example, using the following command: - -ovs-ofctl add-flow br0 in_port=0,actions=output:1 - -The test will be carried out with the functionality to enable high-priority -traffic enabled and disabled in order to guage the change in performance for -both cases. - -Two classes of traffic will be generated by a traffic generator. In the example -above, the classes are differentiated using the Ethernet PCP field. However, -another means for differentiating traffic could be used, depending the -prioritization scheme that is developed. - -Tests should be performed for each combination of: - -* Packet Sizes in (64, 512) -* Total Offered Rate in (80, 120, 150) -* rate_ingress_b(n) / rate_ingress_a(n) in (0.1, 0.2, 0.5) - -For each set, the following metrics should be collected for each traffic -class over a specified time period: - -Egress Throughput (Mfps) -Maximum Egress Latency (ms) -Maximum Egress Jitter (ms) - -Documentation Impact -==================== - -TBD - -References -========== - -Please add any useful references here. You are not required to have any -reference. Moreover, this specification should still make sense when your -references are unavailable. Examples of what you could include are: - -* Links to mailing list or IRC discussions - -- http://lists.opnfv.org/pipermail/opnfv-tech-discuss/2015-December/007193.html -- http://ircbot.wl.linuxfoundation.org/meetings/opnfv-ovsnfv/2016/opnfv-ovsnfv.2016-03-07-13.01.html - -* Links to relevant research, if appropriate - -- https://wiki.opnfv.org/download/attachments/5046510/qos_mechanisms.pdf?version=1&modificationDate=1459187636000&api=v2 - -* Related specifications as appropriate - -* Anything else you feel it is worthwhile to refer to - - -History -======= - -Optional section intended to be used each time the spec -is updated to describe new design, API or any database schema -updated. Useful to let reader understand what's happened along the -time. - -.. list-table:: Revisions - :header-rows: 1 - - * - Release Name - - Description - * - Colorado - - Introduced |