Hello!

I have a question to experienced people with media streaming.

Sometimes we do a video broadcast using realserver. I am watching the video with no problem, and half of the viewers can watch without any problems. Another half of viewers complain about the quality. they are getting slide show and real player is rebuffering every 20-30 seconds, although their speed is good enough to handle the video stream, which is 512 kbit/sec. Even when I got 30 players connected - I do not feel the difference and I cannot check the quality from another locations, I got 99% packets received. Some users say that in "rush hour" your server is overloaded. I cant find where the problem is, what causes this "rebuffering" in real player.

Server is linux RHES on dual xeon 2.8, 2 Gb memory, 100 mbit uplink.

Stream is encoded at 512 kbit/sec.

Check your box/switch and see if it's operating at full-duplex. I've had an issue with streaming WM, was getting major packet loss until I realized the box was at half-dup :(

Originally posted by GideonX
Check your box/switch and see if it's operating at full-duplex. I've had an issue with streaming WM, was getting major packet loss until I realized the box was at half-dup :(

thanks for reply,

How do I check it?

you can use mii-diag for it http://freshmeat.net/projects/mii-diag/

Output from mii-diag:

Using the default interface 'eth0'.
Basic registers of MII PHY #0: 1140 796d 0141 0c23 0de1 4181 0007 2001.
The autonegotiated capability is 0180.
The autonegotiated media type is 100baseTx-FD.
Basic mode control register 0x1140: Auto-negotiation enabled.
You have link beat, and everything is working OK.
Your link partner advertised 4181: 100baseTx-FD 100baseTx.
End of basic transceiver information.


Looks like full duplex is engaged?

Originally posted by igorkl
Output from mii-diag:

The autonegotiated media type is 100baseTx-FD.
Your link partner advertised 4181: 100baseTx-FD 100baseTx.
Looks like full duplex is engaged?

yes, FD is full duplex

I've have a hatred for auto detected speeds, they never seem to work on any of my FreeBSD boxes. I have had to force FD on each and every one of them.

You may need to force full duplex if you are running Cisco switches. They often have problem with auto-negotiation detection except with a very limited set of hardware

you can use mii-diag to force the media type e.g.
mii-diag -F 100baseTx-FD eth0

Setting the speed to "fixed", Control register 2100.
SIOCSMIIREG on eth0 failed: Invalid argument
Basic registers of MII PHY #0: 2100 794d 0141 0c23 0de1 0000 0004 2001.
Basic mode control register 0x2100: Auto-negotiation disabled, with
Speed fixed at 100 mbps, full-duplex.
You have link beat, and everything is working OK.
Link partner information is not exchanged when in fixed speed mode.
End of basic transceiver information.


May be it is because it is already in full duplex?

streaming is a big problem for slow connection....
unless everyone get a broadbane :)

Originally posted by igorkl
Setting the speed to "fixed", Control register 2100.
SIOCSMIIREG on eth0 failed: Invalid argument
Basic registers of MII PHY #0: 2100 794d 0141 0c23 0de1 0000 0004 2001.
Basic mode control register 0x2100: Auto-negotiation disabled, with
Speed fixed at 100 mbps, full-duplex.
You have link beat, and everything is working OK.
Link partner information is not exchanged when in fixed speed mode.
End of basic transceiver information.


May be it is because it is already in full duplex?


...
Basic mode control register 0x2100: Auto-negotiation disabled, with
Speed fixed at 100 mbps, full-duplex.
You have link beat, and everything is working OK.
...

now you have successfully forced 100mbit full duplex, you can ignore the error above

sehe

With autonegotiation off I am getting lots of packet rerequests. Working in autosence mode again.

Linux#/sbin>./mii-tool -r
restarting autonegotiation...
Linux#/sbin>./mii-tool -v
eth0: negotiated 100baseTx-FD, link ok
product info: vendor 00:50:43, model 2 rev 3
basic mode: autonegotiation enabled
basic status: autonegotiation complete, link ok
capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control
link partner: 100baseTx-FD 100baseTx-HD