examples/diffserv/README

   1
   2 Note all these are mere examples which can be customized to your needs
   3
   4 AFCBQ
   5 -----
   6 AF PHB built using CBQ, DSMARK,GRED (default in GRIO mode) ,RED for BE
   7 and the tcindex classifier with some algorithmic mapping
   8
   9 EFCBQ
  10 -----
  11 EF PHB built using CBQ (for rate control and prioritization),
  12 DSMARK( to remark DSCPs), tcindex  classifier and  RED for the BE
  13 traffic.
  14
  15 EFPRIO
  16 ------
  17 EF PHB using the PRIO scheduler, Token Bucket to rate control EF,
  18 tcindex classifier, DSMARK to remark, and RED for the BE traffic
  19
  20 EDGE scripts
  21 ==============
  22
  23 CB-3(1|2)-(u32/chains)
  24 ======================
  25
  26
  27 The major differences are that the classifier is u32 on -u32 extension
  28 and IPchains on the chains extension. CB stands for color Blind
  29 and 31 is for the mode where only a CIR and CBS are defined whereas
  30 32 stands for a mode where a CIR/CBS + PIR/EBS are defined.
  31
  32 Color Blind (CB)
  33 ==========-----=
  34 We look at one special subnet that we are interested in for simplicty
  35 reasons to demonstrate the capability. We send the packets from that
  36 subnet to AF4*, BE or end up dropping depending on the metering results.
  37
  38
  39 The algorithm overview is as follows:
  40
  41 *classify:
  42
  43 **case: subnet X
  44 ----------------
  45   if !exceed meter1 tag as AF41
  46         else
  47             if !exceed meter2  tag as AF42
  48                 else
  49                   if !exceed meter 3 tag as AF43
  50                       else
  51                          drop
  52
  53 default case: Any other subnet
  54 -------------------------------
  55   if !exceed meter 5 tag as AF43
  56       else
  57          drop
  58
  59
  60 One Egress side change the DSCPs of the packets to reflect AF4* and BE
  61 based on the tags from the ingress.
  62
  63 -------------------------------------------------------------
  64
  65 Color Aware
  66 ===========
  67
  68 Define some meters with + policing and give them IDs eg
  69
  70 meter1=police index 1 rate $CIR1 burst $CBS1
  71 meter2=police index 2 rate $CIR2 burst $CBS2   etc
  72
  73 General overview:
  74 classify based on the DSCPs and use the policer ids to decide tagging
  75
  76
  77 *classify on ingress:
  78
  79 switch (dscp) {
  80     case AF41: /* tos&0xfc == 0x88 */
  81         if (!exceed meter1) break;
  82     case AF42: /* tos&0xfc == 0x90 */
  83         if (!exceed meter2) {
  84             tag as AF42;
  85             break;
  86         }
  87     case AF43: /* tos&0xfc == 0x98 */
  88         if (!exceed meter3) {
  89             tag as AF43;
  90             break;
  91         } else
  92           drop;
  93     default:
  94         if (!exceed meter4) tag as BE;
  95         else drop;
  96 }
  97
  98 On the Egress side mark the proper AF tags