# looking for interface ring parameter explanation

## maxime1986

Hello

I have 2 asterisk pbx in my LAN (mine and my flatmate's).

Both of use are doing some torrents, web browsing, etc.

As we consider VoIP the most important traffic we configure some QoS rules (basically PRIO + HTB).

It works great but sometimes we still encounter some sound quality problems.

By discussing with some of my friend I learn that there is some sort of buffer inside the network card itself and, if the traffic is heavy, this buffer can screw up the low latency we are trying to achieve with our QoS.

I looked for information on that "buffer" on the net and found some interesting web site :

http://ieoc.com/forums/p/3835/12301.aspx

But I didn't find documentation for linux... I don't know the unit of TX Ring parameter ethtool is giving to me :

```
% sudo ethtool -g eth0

Ring parameters for eth0:

Pre-set maximums:

RX:      16384

RX Mini:   0

RX Jumbo:   0

TX:      16384

Current hardware settings:

RX:      512

RX Mini:   0

RX Jumbo:   0

TX:      256

```

Could someone explain me what is exactly the "ring" (Is that really the "interface buffer", as I thought ? if it's a buffer why call it ring ?).

What is the unit of "TX" and "RX" ?

Thank you in advance

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## chithanh

I don't think the buffer in the network card is to blame. Much more likely the buffer in the cable/DSL/T1/whatever you are using to connect to the Internet is at fault.

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