Autor: Piotr Kucharski (chopin_at_sgh.waw.pl)
Data: Sun 10 Sep 2000 - 13:29:06 MET DST
Jaroslaw Rafa <raj_at_inf.wsp.krakow.pl> wrote:
>> *P*rimary *R*ate *I*nterface, rodzaj usługi ISDN
> a nie _Premium_ Rate Interface? Mnie sie tak wydawalo...
In the Integrated Services Digital Network (Integrated Services
Digital Network), there are two levels of service: the Basic Rate
Interface (BRI), intended for the home and small enterprise, and the
Primary Rate Interface (Primary Rate Interface in ISDN), for larger
users. Both rates include a number of B-channel and a D-channel. The B
channels carry data, voice, and other services. The D channel carries
control and signaling information.
The Basic Rate Interface consists of two 64 Kbps B channels and one 16
Kbps D channel. Thus, a Basic Rate user can have up to 128 Kbps
service. The Primary Rate consists of 23 B channels and one 64 Kpbs D
channel using a T-1 line or 30 B channels and 1 D channel using an E1
line. Thus, a Primary Rate user on a T-1 line can have up to 1.544
Mbps service or up to 2.048 Mbps service on an E1 line. PRI uses the
Q.931 protocol over the D channel.
The Primary Rate channels are carried on a T-carrier system line (in
the U.S., Canada, and Japan) or an E-carrier line (in other countries)
and are typically used by medium to large enterprises. The 23 (or 30)
B channels can be used flexibly and reassigned when necessary to meet
special needs such as videoconferences. The Primary Rate user is
hooked up directly to the telephone company central office.
p.
To archiwum zostało wygenerowane przez hypermail 2.1.7 : Wed 19 May 2004 - 16:36:40 MET DST