Manual Pages  — NG_CAR

• SYNOPSIS
• DESCRIPTION
• HOOKS
• MODES OF OPERATION
• CONTROL MESSAGES
• SHUTDOWN
• EXAMPLES
• SEE ALSO
• AUTHORS
• BUGS

This algorithm is more polite to the TCP traffic than NG_CAR_SINGLE_RATE.

Traffic shaping is much more polite to the TCP traffic than rate limit on links with bandwidth * delay product less than 6-8 TCP segments, but it consumes additional system resources for queue processing.

struct ng_car_hookconf {
        uint64_t cbs;           /* Committed burst size (bytes) */
        uint64_t ebs;           /* Exceeded/Peak burst size (bytes) */
        uint64_t cir;           /* Committed information rate (bits/s) */
        uint64_t pir;           /* Peak information rate (bits/s) */
        uint8_t  green_action;  /* Action for green packets */
        uint8_t  yellow_action; /* Action for yellow packets */
        uint8_t  red_action;    /* Action for red packets */
        uint8_t  mode;          /* single/double rate, ... */
        uint8_t  opt;           /* color-aware or color-blind */
};

/* possible actions (..._action) */
enum {
    NG_CAR_ACTION_FORWARD = 1,
    NG_CAR_ACTION_DROP,
    NG_CAR_ACTION_MARK
};

/* operation modes (mode) */
enum {
    NG_CAR_SINGLE_RATE = 0,
    NG_CAR_DOUBLE_RATE,
    NG_CAR_RED,
    NG_CAR_SHAPE
};

/* mode options (bits for opt) */
#define NG_CAR_COLOR_AWARE      1
#define NG_CAR_COUNT_PACKETS    2

struct ng_car_bulkconf {
        struct ng_car_hookconf upstream;
        struct ng_car_hookconf downstream;
};

struct ng_car_hookstats {
        uint64_t passed_pkts;   /* Counter for passed packets */
        uint64_t droped_pkts;   /* Counter for dropped packets */
        uint64_t green_pkts;    /* Counter for green packets */
        uint64_t yellow_pkts;   /* Counter for yellow packets */
        uint64_t red_pkts;      /* Counter for red packets */
        uint64_t errors;        /* Counter for operation errors */
};

struct ng_car_bulkstats {
        struct ng_car_hookstats upstream;
        struct ng_car_hookstats downstream;
};