{"id":604,"date":"2018-10-26T22:19:32","date_gmt":"2018-10-26T22:19:32","guid":{"rendered":"http:\/\/feralpacket.org\/?p=604"},"modified":"2018-10-26T22:19:32","modified_gmt":"2018-10-26T22:19:32","slug":"qos-shaping-and-policing-notes","status":"publish","type":"post","link":"https:\/\/feralpacket.org\/?p=604","title":{"rendered":"QoS Shaping and Policing Notes"},"content":{"rendered":"

QoS Shaping and Policing<\/span><\/p>\n

\n– Shaping<\/p>\n

\n\u00a0\u00a0\u00a0\u00a0 -> Delaying the traffic to conform with service level agreement<\/p>\n

\n\u00a0\u00a0\u00a0\u00a0 -> Outgoing<\/p>\n

\n– Policing<\/p>\n

\n\u00a0\u00a0\u00a0\u00a0 -> Punishing the traffic to enforce the service level agreement<\/p>\n

\u00a0\u00a0\u00a0\u00a0 -> Incoming<\/p>\n

<\/p>\n

\nA router cannot send traffic at lower rates then the clock rate\n<\/p>\n

\nContract rate<\/p>\n

\n– Committed information rate (CIR)<\/p>\n

\n\u00a0\u00a0\u00a0\u00a0 -> e.g. – 64 kbps<\/p>\n

\nActual rate<\/p>\n

\n– Clock rate<\/p>\n

\n\u00a0\u00a0\u00a0\u00a0 -> e.g. – 128 kbps<\/p>\n

<\/p>\n

\nProblem<\/p>\n

\n– 500ms of delay is added to all network traffic<\/p>\n

<\/p>\n

\nIn every t sub c, only half of the time traffic is sent as a burst\n<\/p>\n

\nb sub c = t sub c * CIR\n<\/p>\n

\n128000 bps<\/p>\n

\n– In one t sub c = 12800 bits<\/p>\n

\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b sub c = 6400 bits<\/p>\n

<\/p>\n

\nb sub c bucket<\/p>\n

\n– When the bucket is empty, no traffic can be sent<\/p>\n

\n– Bucket will be refilled at the start of every t sub c (interval)2\n<\/p>\n

<\/p>\n

If the bucket is not empty at the start of a t sub c, the excess tokens overflow into the b sub e bucket<\/p>\n

<\/p>\n

If CIR is configured but b sub c and b sub e are not configured, the default values are used<\/p>\n

If the contract rate is less than 320kbps, then the default b sub c is 8000 bps<\/p>\n

<\/p>\n

If the contract rage is more than or equal to 320kbps, then the default t sub c is 25ms<\/p>\n

<\/p>\n

policy-map <name><\/span><\/p>\n

\u00a0class <name><\/span><\/p>\n

\u00a0 shape average <cir> [ b sub c ] [ b sub e ]<\/span><\/p>\n

e.g. – Shape all http traffic at the rate of 128kbps<\/p>\n

\u00a0 \u00a0 \u00a0-> Use the burst size of 16000 bit \/ t sub c<\/p>\n

class-map HTTP<\/span><\/p>\n

\u00a0match protocol http<\/span><\/p>\n

policy-map SHAPE<\/span><\/p>\n

\u00a0class HTTP<\/span><\/p>\n

\u00a0 shape average 12800 1600<\/span><\/p>\n

int s0\/0<\/span><\/p>\n

\u00a0service-policy output SHAPE<\/span><\/p>\n

Dual Rate Shaping<\/span><\/p>\n

\u00a0– CIR<\/p>\n

\u00a0– Peak Information Rate (PIR)<\/p>\n

\u00a0– Allowsurst traffic at full rate (PIR) in every interval<\/p>\n

<\/p>\n

<\/p>\n

policy-map <name><\/span><\/p>\n

\u00a0class <name><\/span><\/p>\n

\u00a0 shape peak <cir> <b sub c> <b sub e><\/span><\/p>\n

Scenario -> 3 classes to be shaped at 64kbps, VOICE, HTTP, default<\/p>\n

policy-map WRONG-ANSWER<\/span><\/p>\n

\u00a0class VOICE<\/span><\/p>\n

\u00a0 shape average 64000<\/span><\/p>\n

\u00a0class HTTP<\/span><\/p>\n

\u00a0 shape average 64000<\/span><\/p>\n

\u00a0class class-default<\/span><\/p>\n

\u00a0 shape average 64000<\/span><\/p>\n

Use nested policy maps<\/p>\n

policy-map CHILD<\/span><\/p>\n

\u00a0class VOICE<\/span><\/p>\n

\u00a0 priority<\/span><\/p>\n

\u00a0class HTTP<\/span><\/p>\n

\u00a0 bandwidth<\/span><\/p>\n

\u00a0class class-default<\/span><\/p>\n

policy-map PARENT<\/span><\/p>\n

\u00a0class class-default<\/span><\/p>\n

\u00a0 shape average 64000<\/span><\/p>\n

\u00a0 service-policy CHILD<\/span><\/p>\n

Policing<\/span><\/p>\n

\u00a0– Punishing the traffic to enforce the service level agreement<\/p>\n

\u00a0 \u00a0 \u00a0-> Traffic rate<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> To control the incoming traffic rate<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0-> Called metering<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> 1 token = 1 byte<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> b sub c = bucket size<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0-> The burst size<\/p>\n

<\/p>\n

The bucket is filled when the burst of packets arrive<\/p>\n

The number of tokens filled in the bucket are calculated by a formula<\/p>\n

<\/p>\n

The faster traffic is sent, the less traffic can be sent<\/p>\n

The slower traffic is sent, the more traffic can be sent<\/p>\n

<\/p>\n

<\/p>\n

Conforming rate<\/p>\n

\u00a0– within the contract<\/p>\n

Exceeding rate<\/p>\n

\u00a0– beyond the contract<\/p>\n

Violating rate<\/p>\n

\u00a0– way beyond the contract<\/p>\n

When a single bucket is used, it is called single rate, two bucket policing<\/p>\n

\u00a0– Single rate = CIR<\/p>\n

\u00a0– Colors = actions<\/p>\n

\u00a0 \u00a0 \u00a0-> Conform<\/p>\n

\u00a0 \u00a0 \u00a0-> Exceed<\/p>\n

Actions<\/span><\/p>\n

\u00a0– drop<\/p>\n

\u00a0– transmit<\/p>\n

\u00a0– set-dscp-transmit <dscp><\/p>\n

\u00a0– set-precedence-transmit <precedence><\/p>\n

\u00a0– set-frde-transmit<\/p>\n

\u00a0 \u00a0 \u00a0-> Frame-Relay Discard Eligible (FRDE)<\/p>\n

policy-map <name><\/span><\/p>\n

\u00a0class <name><\/span><\/p>\n

\u00a0 police <cir> <b sub c> conform-action <action> exceed-action <action><\/span><\/p>\n

When two buckets are used, it is called single rate, three colors<\/p>\n

\u00a0– Single rate = CIR<\/p>\n

\u00a0– Colors = actions<\/p>\n

\u00a0 \u00a0 \u00a0-> Conform<\/p>\n

\u00a0 \u00a0 \u00a0-> Exceed<\/p>\n

\u00a0 \u00a0 \u00a0-> Violate<\/p>\n

<\/p>\n

<\/p>\n

18000 bytes<\/p>\n

\u00a0– First 8000 bytes use b sub c tokens<\/p>\n

\u00a0 \u00a0 \u00a0-> Conforming<\/p>\n

\u00a0– Second 8000 bytes use b sub e tokens<\/p>\n

\u00a0 \u00a0 \u00a0-> Exceeding<\/p>\n

\u00a0– last 2000 bytes are dropped<\/p>\n

\u00a0 \u00a0 \u00a0-> Violating<\/p>\n

policy-map <name><\/span><\/p>\n

\u00a0class <name><\/span><\/p>\n

\u00a0 police 64000 8000 8000 confirm-action transmit exceed-action set-dscp-transmit 0 violate-action drop<\/span><\/p>\n

\u00a0 \u00a0 \u00a0-> 64000 – bps<\/p>\n

\u00a0 \u00a0 \u00a0-> 8000 – bytes<\/p>\n

\u00a0 \u00a0 \u00a0-> 8000 – bytes<\/p>\n

When two buckets and two rates are used, it is called dual rate, three color policing<\/p>\n

Ratio = CIR * PIR<\/p>\n

<\/p>\n

<\/p>\n

b sub c and b sub e buckets are filled<\/p>\n

\u00a0– b sub c tokens are used to send the first 8000 bytes<\/p>\n

\u00a0– For every b sub c token used, one token will be removed from the b sub e bucket<\/p>\n

\u00a0– b sub e tokens are used to send the next 8000 bytes<\/p>\n

\u00a0– The last 2000 bytes are violating<\/p>\n

policy-map <name><\/span><\/p>\n

\u00a0class <name><\/span><\/p>\n

\u00a0 police cir <value> bc <value> pir <value> be <value> conform-action transmit exceed-action set-dscp-transmit AF11 violate-action drop<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

QoS Shaping and Policing<\/p>\n","protected":false},"author":1,"featured_media":586,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[31,45],"class_list":["post-604","post","type-post","status-publish","format-standard","hentry","category-ccie","tag-published","tag-qos"],"_links":{"self":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/604","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=604"}],"version-history":[{"count":1,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/604\/revisions"}],"predecessor-version":[{"id":616,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/604\/revisions\/616"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/media\/586"}],"wp:attachment":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=604"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=604"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=604"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}