Tölvumál - 01.06.1997, Side 9

TÖLVUMÁL
Staðall í bundnu máli
Það er ekki á hverjum degi sem staðlanefndir ljúka störfum með því að lýsa verkum sínum í bundnu máli.
Það gerðist þó fyrir árið 1983 þegar ein nefnda CCITT gaf þetta út:
1.412 Summary Poem
Oh, a channel fit for the user's bits
Is the wonderful channel B.
When transparent it delivers what's sent
And at a very low fee.
At sixty-four k this can be the way
To get users data through.
When nontransparent your voice can be sent
Using coding laws A or mu.
To make a connect so things can be sent
You need this other channel “D”.
The signalling goes in a very smooth flow
With packet information “p”.
The speed is defined at a later time
With channel structures shown below.
Link ievel should be procedure LAP D
Which is the one we all love and know.
With higher speeds there is a need
For the larger channel H-zero.
Three hundred eighty-four kilobits (no more)
Is the rate at which this channel goes.
The programme sound encoding is found
Defined by Study Group fifteen.
But the user may find that various kinds
Of submultiplexing solve his needs.
There's lots of fun when controversy comes
On the speed used for H-one.
This channel size cannot be disguised:
Nineteen-twenty kilobits is one.
But some of us say North America's way
Is the path out of this tough fix.
And NTT does also agree
That it should be fifteen thirty six.
A structure shows how the channels go
Across the users interface.
The basic one that can be done
Uses D at sixteen k.
Two B-channels and one D-channel
Make up the basic channel scheme.
The capability that the user sees
May have one or both B's missing.
JÚNÍ1997 -9