NetComm Roadster Series 56K USB Modem

H<value>—Hook Control

Instructs the modem to go on-hook to disconnect a call or go off-hook to make the telephone line busy.

Result codes:

_ OK if <value> = 0—1.

_ ERROR if <value> 0—1.

Command

H0

H1

Function

The modem goes on-hook (default).

The modem goes off-hook.

M<value>—Speaker Control

Use this command to turn the speaker on and off. Result codes:

_ OK if <value> = 0—3.

_ ERROR if <value> 0—3.

Command

M0

M1

M2

M3

Function

Speaker is off.

Speaker is on until the modem detects the carrier signal (default).

Speaker is always on when the modem is off-hook.

Speaker is on until the carrier is detected, except when dialing.

N<value>—Modulation Handshake

Use this command to set the modem protocol for handling handshake negotiation at connection time if the communication speed of the remote modem is different from the speed of the local modem.

Result codes:

_ OK if <value> = 0—1.

_ ERROR if <value> 0—1.

O<value>—Return to On-Line Data Mode

Use this command to exit on-line command mode and re-enter on-line data mode. If the modem is not in on-line command mode when this command is received the modem generates an ERROR result code.

Result codes:

_ CONNECT if <value> = 0, 1, 3 and the result code and call progress monitor is set to 0 (X0).

_CONNECT <rate> if <value> = 0, 1, 3 and the result code and call progress monitor is not set to 0 (X<value> where n = 1-7).

_ NO CARRIER if the connection is not successfully resumed.

_ERROR if <value> 0—1, 3.

Command

Function

 

 

O0

Instructs the modem to exit on-line command mode and return to data mode

 

 

O1

Issues a retrain before returning to on-line data mode.

 

 

O3

Issues a rate renegotiation before returning to on-line data mode.

 

 

m506

NetComm Roadster sSeries 56K UsBS mModem

www.netcomm.com.au

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Nortel Networks 56K manual Hvalue-Hook Control, Mvalue-Speaker Control, Nvalue-Modulation Handshake

56K specifications

Nortel Networks, a leading telecommunications equipment manufacturer, played a crucial role in the development of modem technology during the late 1990s and early 2000s. Among its most notable contributions was the Nortel Networks 56K modem. Introduced at a time when dial-up internet access was the norm, the 56K modem represented a significant leap forward in data transmission speeds for both residential users and businesses alike.

One of the main features of the Nortel Networks 56K modem was its ability to achieve faster data rates compared to its predecessors. While earlier modems operated at speeds of 28.8 Kbps or 33.6 Kbps, the Nortel 56K modem could theoretically reach connection speeds of 56 Kbps under optimal conditions. This enhancement was made possible through the implementation of newer modulation techniques, such as Pulse Amplitude Modulation (PAM), which allowed for more efficient data transmission over standard telephone lines.

The 56K modem was designed to work effectively over existing analog phone lines, which was a crucial characteristic during that time. It could connect directly to the existing Public Switched Telephone Network (PSTN), making it accessible for millions of users without the need for any special infrastructure upgrades. This meant that both home users and businesses could benefit from the increased speed without significant investment.

Another notable feature was the robustness of the Nortel 56K modem's error correction capabilities. Technologies such as V.42 and V.42bis compression were integrated to enhance data integrity. These error-correcting protocols stitched together fragmented data packets, thereby ensuring reliable and stable connections, even over less-than-perfect phone lines. This reliability was vital for users who relied on modems for email, file transfers, and browsing the web.

In terms of compatibility, the Nortel Networks 56K modem was designed to work seamlessly with various operating systems, ensuring that users could connect to the internet regardless of their hardware setup. The plug-and-play capability made installation straightforward, allowing users to start browsing the web quickly.

While the Nortel Networks 56K modem was eventually eclipsed by DSL and broadband technologies that offered even higher speeds, it played an instrumental role in transitioning users from slower modems to a more connected world. The impact of Nortel's 56K modem can still be felt today, as it laid the groundwork for future innovations in digital communications and paved the way for the fast-paced internet landscape we experience now.