HUT Comms.
Lab, Timo O. Korhonen
30
Symmetry
nCategories:
nSymmetrical channel as in fixed line telephony
nAsymmetrical channel
nMost technical Internet realizations (As
xDSL-techniques or data over DVB,
ADSL: 64 kb/s DL, 256 kb/s and up UL) are based on idea that downlink traffic is much larger that uplink traffic (in
Welho® (by HTV) connections 525 kb/s DL, 120 kb/s UL)
nPoint-to-multipoint channel
nTV and Fax are point-to-multipoint
distributive services
nNote, however that some new (peer-to-peer)
services in Internet (where your PC
works as a server, using Gnutella network) might require symmetrical traffic channel
nAlso Internet is used for point-to-multipoint
(multicast) services as in Webcasting
(as in Web-broadcasting or in the PointCast news service.)
nTherefore
developing Internet services set stringent requirements for network infrastructure
& planning!