Samsung Ubigate iBG2016, Руководство по настройке

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CHAPTER 10. QoS
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Traffic Policing Functionality on iBG2016
Customers will now be able to rate limit inbound traffic on the WAN links
using policing while doing CBQ for outbound traffic. This means the
iBG2016 can now provide QoS for traffic in both directions, eliminating
dependency on the upstream router. Policing of outbound WAN traffic is also
possible, but using CBQ to shape traffic is recommended because of reasons
mentioned in section ‘Traffic Policing versus Traffic Shaping’.
Additionally, CBQ in iBG2016 OS also provides bandwidth guarantee,
bandwidth borrowing and prioritization. It provides ‘Total Link Access
Control’ instead of just rate limiting.
Traffic policing is also supported on Ethernet interfaces. Please check section
‘Verifying Policing Status and Configuration’ for limitations.
Traffic policing is implemented using a token bucket algorithm. Users will be
able specify two parameters when configuring traffic policing, Rate(token fill
rate) and Peak(number of tokens). Rate is specified in
Kbps . Peak can be
specified in kilobits or as a duration(based on the configured rate) in
milliseconds . ‘Rate’ determines the average bandwidth for the policed flow
and ‘Peak’ determines the maximum peak(in bits or bytes) permitted for the
flow. Packets conforming to these limits will be forwarded and those violating
these limits will be dropped.
Specifying just the ‘Rate’ and ‘Peak’ makes the policing feature simple and
effective. The ‘extended peak’ parameter is needed to permit a large packet,
by loaning tokens, when there are not enough tokens available at a given time
for the entire packet. The iBG2016 policing algorithm allows for such
‘loaning of tokens’ by default.
Configuring Traffic Policing
As with CBQ, the first step is traffic classification. Flows should be defined
by creating traffic classes. To classify based on multiple fields, for example,
source IP address and port, a hierarchy of classes should be created. Traffic
policing for a class can be configured using the ‘police’ command at the class
level as shown below. Policing for non-leaf classes(which define more
aggregate flows) is currently not be supported. Multi-level policing will be
supported in a later release.