| Description | The maximum shaping delay in milliseconds. That is, the
maximum amount time of buffering the CMTS will allow for
any rate exceeded flow. If the max buffering delay is
large, the grants/packets of the flow will be buffered for
a longer period of time even though the flow is rate
exceeded. This means fewer chances of drops for such rate
exceeded flow. However, too large a max shaping delay
can result is quick drainage of packet buffers at the CMTS,
since several packets will be in the shaping (delay) queue
waiting for their proper transmission time. Another
important point to be noted is that delaying a flows packets
(especially TCP flows) for extended periods of time is
useless, since the higher protocol layers may assume a
packet loss after a certain amount of time.
The maximum shaping delay is only applied to rate limit
algorithm:
Token bucket algorithm with shaping. If the rate limit
algorithm is not Token bucket algorithm with shaping, the
value is always na(1) which is not applicable.
If the token count is less than the size of request/packet,
CMTS computes the shaping delay time after which the deficit
number of tokens would be available. If the shaping delay
time is greater than the maximum shaping delay, the
request/packet will be dropped.
The enumerations for maximum shaping delay are:
na(1): maximum shaping delay is not applied to the current
rate limit algorithm
msec128(2): maximum shaping delay is 128 milliseconds
msec256(3): maximum shaping delay is 256 milliseconds
msec512(4): maximum shaping delay is 512 milliseconds
msec1024(5): maximum shaping delay is 1024 milliseconds
The downstream maximum shaping delay is configurable and the
default value is msec128(2). Whenever the downstream rate
limit algorithm is changed to Token bucket algorithm with
shaping from other rate limit algorithm, the value will
be reset to the default value.
The upstream maximum shaping delay is not configurable and
it is read-only value. |