Cabletron Systems CSMIM-T1 Manual De Usuario
Error Correction
CSMIM-T1 Hardware Installation Guide
6-15
Other Classes of MNP
MNP Class 2 uses standard asynchronous framing techniques for data
transmission and error correction. Because of this protocol overhead, the
actual throughput is less than the bps rate of the modem.
transmission and error correction. Because of this protocol overhead, the
actual throughput is less than the bps rate of the modem.
MNP Class 3 uses synchronous framing techniques. Removing start and
stop bits associated with each character prior to transmitting results in a
20% performance increase over Class 2. Thus, actual throughput is
greater than the modem’s bps rate.
stop bits associated with each character prior to transmitting results in a
20% performance increase over Class 2. Thus, actual throughput is
greater than the modem’s bps rate.
MNP Class 4 uses synchronous framing techniques plus improvements
developed by Microcom Adaptive Packet Assembly and Optimized Data
Phase. These enhancements result in better performance for all types of
connections.
developed by Microcom Adaptive Packet Assembly and Optimized Data
Phase. These enhancements result in better performance for all types of
connections.
Adaptive Packet Assembly automatically adjusts the size of the data
packets based on the quality of the telephone line. When the line quality is
good and there are few retransmissions, the modem increases the packet
size. When the line quality is poor and retransmissions are frequent, the
size of the packet decreases in order to maintain high throughput during
error correction under poor conditions.
packets based on the quality of the telephone line. When the line quality is
good and there are few retransmissions, the modem increases the packet
size. When the line quality is poor and retransmissions are frequent, the
size of the packet decreases in order to maintain high throughput during
error correction under poor conditions.
Optimized Data Phase is the redesign of the MNP protocol header that
reduces the number of overhead bytes per data packet. For example,
modems operating at Class 4 service transmit data at 2,900 bps.
reduces the number of overhead bytes per data packet. For example,
modems operating at Class 4 service transmit data at 2,900 bps.
MNP Class 6 allows half-duplex, fast-train, high-speed reliable
connections with other MNP Class 6 modems at speeds of 4,800 to
9,600 bps.
connections with other MNP Class 6 modems at speeds of 4,800 to
9,600 bps.
Universal Link Negotiation allows the modem to automatically connect
with other MNP modems at the highest common speed and protocol.
with other MNP modems at the highest common speed and protocol.
Statistical Duplexing
adjusts the line bandwidth and data traffic flow
during reliable connections to achieve maximum throughput.
MNP Class 7 provides Enhanced Data Compression, which combined
with Class 4 allows throughput of more than twice the connection speed.
MNP Class 7 Enhanced Data Compression not only dynamically adjusts
to the type of data being transmitted, but allows for the probability of
character frequency, for superior compression efficiency.
with Class 4 allows throughput of more than twice the connection speed.
MNP Class 7 Enhanced Data Compression not only dynamically adjusts
to the type of data being transmitted, but allows for the probability of
character frequency, for superior compression efficiency.
MNP Class 9 includes enhanced Universal Link Negotiation.