{"id":564,"date":"2018-10-26T22:13:55","date_gmt":"2018-10-26T22:13:55","guid":{"rendered":"http:\/\/feralpacket.org\/?p=564"},"modified":"2018-10-26T22:13:55","modified_gmt":"2018-10-26T22:13:55","slug":"quality-of-service-qos-notes","status":"publish","type":"post","link":"https:\/\/feralpacket.org\/?p=564","title":{"rendered":"Quality of Service (QoS) Notes"},"content":{"rendered":"

Quality of Service (QoS)<\/span>\u00a0<\/p>\n

\u00a0– Managed unfairness<\/p>\n

\u00a0– Problem with QoS is you will not see any results unless there is traffic congestion<\/p>\n

\u00a0 \u00a0 \u00a0-> It’s hard to generate a variety of different types of traffic<\/p>\n

\u00a0 \u00a0 \u00a0-> During the lab, they are not expecting to you to generate traffic to verify the configuration<\/p>\n

\u00a0 \u00a0 \u00a0-> They will only verify your configuration<\/p>\n

Instructor comment, “Bandwidth and sex, there is never enough.”<\/p>\n

Bandwidth<\/p>\n

\u00a0 \u00a0 \u00a0-> Traffic rate (width of the pipe)<\/p>\n

Propagation\u00a0Delay<\/p>\n

\u00a0 \u00a0 \u00a0-> The time is takes to get from point A to point B (length of the pipe)<\/p>\n

Serialization Delay<\/p>\n

\u00a0 \u00a0 \u00a0-> The time it takes to send traffic from the interface to the media<\/p>\n

\u00a0 \u00a0 \u00a0-> Delay = Amount of data \/ clock rate<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Clock rate of the interface<\/p>\n

Jitter<\/p>\n

\u00a0 \u00a0 \u00a0-> Variance in delay<\/p>\n

QoS Architecture<\/span><\/p>\n

\u00a0– Integrated QoS<\/p>\n

\u00a0 \u00a0 \u00a0-> End-to-end QoS<\/p>\n

\u00a0– Differential Service QoS<\/p>\n

\u00a0 \u00a0 \u00a0-> Per-hop QoS<\/p>\n

Integrated Services QoS<\/span><\/p>\n

<\/p>\n

Resource Reservation Protocol (RSVP)<\/span><\/p>\n

\u00a0– Path message set to destination and waits for a reservation message response before sending traffic<\/p>\n

\u00a0– If any router disagrees with Path, it will be dropped and no traffic will be sent<\/p>\n

Diff Serv<\/span><\/p>\n

\u00a0– The first hop router will mark the important traffic and hope that other routers\u00a0agrees\u00a0with the markings<\/p>\n

\u00a0– Mark the traffic and hope for the best<\/p>\n

\u00a0– Per hop behavior (PHB)<\/p>\n

Differential Service<\/span><\/p>\n

\u00a0– Marking of packet<\/p>\n

\u00a0 \u00a0 \u00a0-> Layer 3<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> IP header<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> IP Precedence \/ Differential Service Code Point (DSCP)<\/p>\n

\u00a0 \u00a0 \u00a0-> Layer 2<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Frame header<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Class of Service (CoS)<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0-> 802.1q tag<\/p>\n

IP Header<\/p>\n

\u00a0– 8 bit field called Type of Service (ToS)<\/p>\n

<\/p>\n

IP\u00a0Precedence\u00a0(IPP)<\/span><\/p>\n

\u00a0– Higher is better<\/p>\n

\u00a0 \u00a0 \u00a0-> 0 – Routine<\/p>\n

\u00a0 \u00a0 \u00a0-> 1 –\u00a0Priority<\/p>\n

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

\u00a0 \u00a0 \u00a0-> 2 – Immediate<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Video\u00a0signaling<\/p>\n

\u00a0 \u00a0 \u00a0-> 3 – Flash<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Voice\u00a0signaling<\/p>\n

\u00a0 \u00a0 \u00a0-> 4 – Flash Override<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Video stream<\/p>\n

\u00a0 \u00a0 \u00a0-> 5 – Critical<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Voice stream<\/p>\n

\u00a0 \u00a0 \u00a0-> 6 – Internetwork<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Management protocol<\/p>\n

\u00a0 \u00a0 \u00a0-> 7 – Network<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Management protocol<\/p>\n

<\/p>\n

Priority Values<\/span><\/p>\n

\u00a0 \u00a0 \u00a0-> 0 – Default<\/p>\n

\u00a0 \u00a0 \u00a0-> 1 – Assured Forwarding (AF)<\/p>\n

\u00a0 \u00a0 \u00a0-> 2 – Assured Forwarding (AF)<\/p>\n

\u00a0 \u00a0 \u00a0-> 3 – Assured Forwarding (AF)<\/p>\n

\u00a0 \u00a0 \u00a0-> 4 – Assured Forwarding (AF)<\/p>\n

\u00a0 \u00a0 \u00a0-> 5 – Expedited Forwarding (EF)<\/p>\n

\u00a0 \u00a0 \u00a0-> 6 – Internetwork<\/p>\n

\u00a0 \u00a0 \u00a0-> 7 – Network<\/p>\n

Drop Precedence<\/span><\/p>\n

\u00a0– Only works with AF<\/p>\n

\u00a0– 2^2 = 4 Drop\u00a0Precedence\u00a0Values<\/p>\n

\u00a0 \u00a0 \u00a0-> 0 0 = 0 -> Never used<\/p>\n

\u00a0 \u00a0 \u00a0-> 0 1 = 1<\/p>\n

\u00a0 \u00a0 \u00a0-> 1 0 = 2<\/p>\n

\u00a0 \u00a0 \u00a0-> 1 1 = 3<\/p>\n

AF X Y<\/p>\n

\u00a0– X – Priority Value<\/p>\n

\u00a0 \u00a0 \u00a0-> Higher is better<\/p>\n

\u00a0– Y – Drop\u00a0Precedence<\/p>\n

\u00a0 \u00a0 \u00a0-> Lower is better<\/p>\n

AF1 \u00a0 \u00a0 -> \u00a0 \u00a0 AF11 \u00a0 \u00a0 AF12 \u00a0 \u00a0 AF13<\/p>\n

AF2 \u00a0 \u00a0 -> \u00a0 \u00a0 AF21 \u00a0 \u00a0 AF22 \u00a0 \u00a0 AF23<\/p>\n

AF3 \u00a0 \u00a0 -> \u00a0 \u00a0 AF31 \u00a0 \u00a0 AF32 \u00a0 \u00a0 AF33<\/p>\n

AF4 \u00a0 \u00a0 -> \u00a0 \u00a0 AF41 \u00a0 \u00a0 AF42 \u00a0 \u00a0 AF43<\/p>\n

AF23 \u00a0 \u00a0 -> Priority 2 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> 010<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Drop Precendence 3 \u00a0 \u00a0 \u00a0 \u00a0 -> 11<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Last bit \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0-> 0<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0DSCP Value – 010110 = 22 in decimal<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Don’t need to know for the lab, but need to know for the written<\/p>\n

AF X Y = ( 8X + 2Y )<\/p>\n

AF23 \u00a0 = ( 8*2 + 2*3 ) = 22<\/p>\n

Modular QoS CLI (MQC)<\/span><\/p>\n

\u00a0– Old configuration was directly in global config<\/p>\n

\u00a0– Class-map<\/p>\n

\u00a0 \u00a0 \u00a0-> Matching procedure<\/p>\n

\u00a0 \u00a0 \u00a0-> Classifying the data<\/p>\n

\u00a0– Policy-map<\/p>\n

\u00a0 \u00a0 \u00a0-> Defines the action<\/p>\n

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

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

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

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

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

\u00a0– Service-policy<\/p>\n

\u00a0 \u00a0 \u00a0-> Implement the policy-map<\/p>\n

\u00a0 \u00a0 \u00a0-> Inside interface configuration<\/p>\n

\u00a0 \u00a0 \u00a0-> In | out direction<\/p>\n

Class-map<\/p>\n

class-map [match-any | match-all] <name><\/span><\/p>\n

\u00a0match <condition><\/span><\/p>\n

match [ip] precedence <up to 4 comma separated values><\/span><\/p>\n

\u00a0– ip option<\/p>\n

\u00a0 \u00a0 \u00a0-> If used, then only IPv4 packets are checked<\/p>\n

\u00a0 \u00a0 \u00a0-> Otherwise, both IPv4 and IPv6 packets are checked<\/p>\n

match [ip] dscp <up to 8 different vlaues><\/span><\/p>\n

\u00a0 \u00a0 \u00a0-> match dscp AF11 AF12<\/span><\/p>\n

match cos <up to 4 values><\/span><\/p>\n

match address-group <acl> [ip address]<\/span><\/p>\n

\u00a0 \u00a0 \u00a0-> IP addresses and port numbers<\/p>\n

match source-address mac <mac address><\/span><\/p>\n

match destination-address mac <mac address><\/span><\/p>\n

match mpls experimental [topmost] <value><\/span><\/p>\n

Network Based Application Recognition (NBAR)<\/p>\n

\u00a0– Performs deep packet inspection<\/p>\n

match protocol <name><\/span><\/p>\n

match packet length min <value> max <value><\/span><\/p>\n

\u00a0 \u00a0 \u00a0– Only min or max needs to be specified, or both<\/p>\n

match input-interface <int><\/span><\/p>\n

Voice Traffic<\/p>\n

\u00a0– Real-time Transport Protocol (RTP)<\/p>\n

\u00a0 \u00a0 \u00a0-> Port numbers<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> 16384 – 32767<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Even port number<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0-> Voice traffic<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Odd port number<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0-> Voice signal<\/p>\n

\u00a0 \u00a0 \u00a0-> Best way to match is to use NBAR<\/p>\n

match protocol rtp audio<\/span><\/p>\n

\u00a0 \u00a0 \u00a0– or –<\/p>\n

match ip rtp <start of range> <range><\/span><\/p>\n

\u00a0 \u00a0 \u00a0– start of range is a port number<\/p>\n

match ip rtp 100 50<\/span><\/p>\n

\u00a0 \u00a0 \u00a0-> Ports 100 – 150<\/p>\n

match ip rtp 16384 16384<\/span><\/p>\n

\u00a0 \u00a0 \u00a0-> Matches the entire RTP port range<\/p>\n

match not <condition><\/span><\/p>\n

match class <class-map name><\/span><\/p>\n

\u00a0 \u00a0 \u00a0-> For nesting class-maps for advanced matching scenarios<\/p>\n

Policy-map<\/p>\n

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

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

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

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

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

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

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

\u00a0 \u00a0 \u00a0-> All traffic not matching other classes<\/p>\n

Class-map Actions<\/span><\/p>\n

\u00a0– Marking<\/p>\n

\u00a0– Queueing<\/p>\n

\u00a0– Shaping<\/p>\n

\u00a0– Policing<\/p>\n

\u00a0– Dropping<\/p>\n

\u00a0– Random-detect<\/p>\n

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

\u00a0service policy { input | output } <name of policy-map><\/span><\/p>\n

sh policy-map interface <int><\/span><\/p>\n

Classification and Marking<\/span><\/p>\n

<\/p>\n

Scenario -> R1 is the edge router. \u00a0Mark all incoming voice traffic with DSCP EF. \u00a0Mark all incoming http traffic with AF31. \u00a0All other traffic should be marked “default”.<\/p>\n

R1(config)# class-map CLASS1<\/span><\/p>\n

\u00a0match protocol rtp audio<\/span><\/p>\n

class-map CLASS2<\/span><\/p>\n

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

policy-map POLICY1<\/span><\/p>\n

\u00a0class CLASS1<\/span><\/p>\n

\u00a0 set dscp ef<\/span><\/p>\n

\u00a0class CLASS2<\/span><\/p>\n

\u00a0 set dscp AF31<\/span><\/p>\n

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

\u00a0 set dscp default<\/span><\/p>\n

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

\u00a0service-policy input POLICY1<\/span><\/p>\n

sh policy-map int s0\/0<\/span><\/p>\n

Queueing<\/span><\/p>\n

\u00a0– Congestion Management<\/p>\n

<\/p>\n

e.g. – Clock rate 64000bps<\/p>\n

\u00a0 \u00a0 \u00a0-> But if traffic rate is 96000bps<\/p>\n

<\/p>\n

Congestion<\/span><\/p>\n

\u00a0– If there HW queue is full and more traffic is waiting to be sent<\/p>\n

Software Queue<\/span><\/p>\n

\u00a0– Collection of pointers to the memory locations where the packets are located<\/p>\n

\u00a0– FIFO queue<\/p>\n

<\/p>\n

Tail Drop<\/span><\/p>\n

\u00a0– What happens when the HW queue and Software queue is full<\/p>\n

To change the hardward queue-length<\/span><\/p>\n

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

\u00a0tx-ring-limit <number><\/span><\/p>\n

To change the software queue-length<\/span><\/p>\n

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

\u00a0hard-queue <number> out<\/span><\/p>\n

To display the HW Queue<\/span><\/p>\n

sh controllers s0\/0<\/span><\/p>\n

\u00a0. . .<\/p>\n

\u00a0. . .\u00a0<\/p>\n

\u00a0. . .<\/p>\n

tx-limit x(y)<\/p>\n

\u00a0 \u00a0 \u00a0-> x – 0 -> default sofware queue<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 1 -> advanced queueing<\/p>\n

\u00a0 \u00a0 \u00a0-> y – queue-length<\/p>\n

tx-limit 0(16)<\/p>\n

\u00a0 \u00a0 \u00a0-> Default for most routers<\/p>\n

tx-limit 0(128)<\/p>\n

\u00a0 \u00a0 \u00a0-> IOU routers<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> This could cause unexpected results if QoS was first tested in an IOU environment<\/p>\n","protected":false},"excerpt":{"rendered":"

Quality of Service (QoS)\u00a0<\/p>\n","protected":false},"author":1,"featured_media":557,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[31,45],"class_list":["post-564","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\/564","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=564"}],"version-history":[{"count":1,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/564\/revisions"}],"predecessor-version":[{"id":607,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/564\/revisions\/607"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/media\/557"}],"wp:attachment":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=564"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=564"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=564"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}