Total Control MP/16, Operator'S Manual

Page: 85 / 182

Cellular 4-7
ETC
When ETC is enabled, the modems recognize calls from other
modems using ETC and alter settings for increased performance
when transmitting data across cellular links.
ETC requires that the modems establish V.42 error control. ETC
also requires a V.32
bis
, V.32, or V.22-type connection. ETC does
not function under V.34 modulation.
The modem uses ETC whenever it answers a call and receives the
ETC calling tone. The modem must receive the ETC calling tone
from the originating modem. It is the only way for the modem to
know that it will be transmitting over a cellular link. If the modem
does not receive the ETC calling tone, the call progresses normally
without ETC settings.
Originating Non-Cellular Calls
When enabled for ETC, the modem implements ETC settings for all
outgoing calls. Even if it is not connecting across a cellular link, the
modem forces a V.32- or V.22-type modulation and V.42 with a
reduced packet size, and will not connect using V.34. It also
transmits using de-emphasis and reduced transmit level, which
results in reduced throughput or even dropped calls. If the modem
is going to be used for originating calls across non-cellular links, we
recommend using the
Disable ETC During Originate Mode
setting
(S66.7=1).
Cellular Templates
Three cellular templates stored in the modem’s ROM allow you to
activate ETC or MNP10 with the modem settings that offer
maximum performance.
A template may be loaded in one of three ways:
♦
By using the Modem Software Commands from the Commands
window if you are using
Total Control Manager/SNMP
(TCM)
.
♦
By using the Total Control Modem MIB command table if you
are using other SNMP management software.
♦
By using the &F
n
command if you are using AT commands to
configure the modems.