Page 1 of 1
In general, did older devices change into modems; while newer ones, into Etherent?
Posted: 19 Mar 2021, 20:28
In general, is it a correct statement that most newer devices change mode into an Ethernet like device? Where an Ethernet like device is in contrast to a modem, ttyUSB, device that most older generations of the devices used to changed into?
Is it a correct statement that, in general, with newer devices, the user has no access to the underline modem device, if there is one at all?
Re: In general, did older devices change into modems; while newer ones, into Etherent?
Posted: 17 Apr 2021, 14:01
Yes, you could say that.
When wireless USB modems emerged, there wasn't much choice regarding drivers. So they mostly chose the USB simulation of a serial port, like it was used on analogue landline modems. The drivers and the overlaying tools (pppd) were widely available.
However, that serial protocol isn't optimized for WAN connections. Lots of old gruft and overhead. So new, optimzed protocols for USB were standardized, like ECM and NCM (with MBIM sitting on it). However, the step of connecting is still approached from several sides.
The Huawei NCM driver opens a sort of AT interface that can be used to setup and control the modem with classic AT commands (but not for the actual connection).
ECM devices usually start connecting when their internal DHCP server is asked for an IP address
Most computers support those new standards by now. It the modem manufacturers care, they provide some sort of fall-back mode with classic ttyUSB emulation.