Joined: 16 Jul 2002
Location: New Zealand
|Posted: Sat Aug 10, 2002 8:39 am Post subject: Low latency flag for serial ports on modems
|I experimented for a couple of weeks with different flags on my 56k modem on the serial port.
The serial port my modem use is /dev/ttyS3.
I found that adding the low_latency flag provides a bit more burst speed.
My speed often goes up to 115200bps which is the maximum my modem can handle...
These are burst speeds but still browsing the net is better with this setting.
As root add the low_latency flag to your serial port: see man setserial
I just add this line to my /etc/conf.d/local.start
## speed up my 56k ISA hardware modem
/bin/setserial /dev/ttyS3 uart 16550A irq 3 low_latency
So it gets set at each boot.
You should see something like:
[root@babe pts/0] setserial -a /dev/ttyS3
/dev/ttyS3, Line 3, UART: 16550A, Port: 0x02e8, IRQ: 3
Baud_base: 115200, close_delay: 5000, divisor: 0
Flags: spd_normal low_latency
you see the flag on the bottom raw above.
I tried the spd_vhi flag but it appears that low_latency provides the best result for me.
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