Specifications

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UHP-1000 SATELLITE ROUTER

INSTALLATION AND OPERATION MANUAL, V. 2.5

(SW VERSION 2.5.X)

cannot guarantee CIR streams – this is just impossible, but anyway it will try to provide maximum fair

distribution of the bandwidth.

TS adjustment commands:

---------- Traffic Shaper parameters

shaper stream 0-500 0-64000 [0-64000] - TS stream CIR(Kbps) [MAXSPEED(Kbps)]

Stream parameter adjustment. Guaranteed bit rate (CIR) and optionally – maximum stream bit rate

are set. If maximum bit rate is not set, stream bit rate will be tantalizingly constrained by CIR. Stream

bit rates are measured in kilobit per second (1024 bit/s). When selecting stream numbers it is better

to number them from the beginning and not to use too large numbers (numbering 100, 200, 300... is

undesirable, better numbers are 1, 2, 3 or 2, 4, 6).

shaper delete 0-500 - Delete TS stream

Nulls stream parameters by switching this stream over to TS transparent algorithm.

shaper total bandwidth 0-128000 - Composite channel bandwidth (Kbps)

Output bandwidth limit to which TS algorithm will reference to. This is not a tough (monitored) value

but a desirable one – with sharp changes in traffic at the input, the TS output traffic may exceed this

value. It is expedient to first set the TS bandwidth 5% less than the channel bandwidth and then

correct it while observing the network traffic.

shaper slope 1-64 - Shaper algorithm slope factor

Relative non-dimensional coefficient (a multiple) monitoring how TS is adapting (increasing) streams

bandwidth. Value 16 is optimum to begin with, and it can be corrected if necessary.

TS settings and statistics can be observed using “show shaper” command.

UHP#sh sh

Slope=16 Bandwidth(K)=64000 ModSpeed(Bps)=0(0%) ModDelay(s)=0.0

1 | 100 0 | 0 0 | 0.0 | 0 0 0 |

5 | 256 384 | 0 0 | 0.0 | 0 0 0 |

Slope - Bandwidth adaptation coefficient.

Bandwidth - Desirable TS output bandwidth.

ModSpeed - modulator traffic rate in kilobits and in per cent of the modulator maximum possible

bandwidth (physical).

ModDelay - Delay on the modulator in seconds (queues length / bit rate).

Strm - Stream number.

CIR.K - Assigned certified information rate.

Max.K - Assigned maximum permissible bit rate.

Spd.bps - Current bit rate at the stream output in bits per second and per cent. Per cent is

calculated with reference to CIR.

Del - Delay on the stream is seconds (queues length / bit rate).

LowSp,... - Bit rates in each queue inside the stream.

Title - Stream name (for CS). Setting is performed only from NMS and transmitted to the

router on the network.

2.12 TCP Acceleration

Acceleration of TCP traffic can be divided into two phases: accelerating TCP-connections and accelerating data

transfer over TCP.

In satellite networks with high traffic load and large number of users connected to the Internet, most relevant is

acceleration of TCP connection. Quite often, a number of TCP connections required to display just one web page

because of different sources of information in the network (images, logos, sponsors, partners, advertising banners

and so on). Unavoidable delays of satellite connections may lead to a significant slowdown in downloading web

sites. In such circumstances even acceleration of TCP traffic gives no essential benefits, because typical network

serves a large number of users and normally completely loaded by traffic, so acceleration of particular TCP sessions

by occupying idle network resources is not always possible.