In the example above the timeslots 3 through 7 are used to carry voice
channels and the timeslot 16 is used to transmit signaling. The modem
recognizes all those timeslots as payload data, so the required DSL rate is
384 kbps.
3.4.6 E1 interface behavior in the Automatic DSL rate selection mode
E1 interface operation of the SG-16G modems has a number of features in
the automatic DSL rate selection mode.
The number of transmitted timeslots may vary from one connection session
to another since the DSL rate is selected automatically per each connection
session.
In this mode the timeslot map defines timeslot numbers that are subject to
transmit through DSL regardless a selected rate so a total amount of those
timeslots specifies the lowest permitted rate.
The link remains down if the line provides no such rate. Additional timeslots
can be transmitted if the link rate exceeds the lowest permitted rate. Those
slots are marked in the map by (+) sign upon DSL link activation.
: dsl
DSL: Rate=Auto 1408 of 2304 kbit/s Code TCPAM16 SLAVE – ONLINE
: e1 map
E1A: Long-Haul FRAMED Code=HDB3 – ONLINE
0 . 1 . 2 . 3
01234567890123456789012345678901
---**************++++++---------
Used timeslots: 16 Payload: 1024 kbit/s
:
In the example above timeslots 1 through 16 are required to transmit
(marked by asterisk “*”) so that demands 1024 Kbps DSL rate. Upon the link
activation the actual rate (1408 kbps) exceeds the lowest permitted rate so 6
34
