Subject: Re: Comments to "Advice for Internet Subnetwork Designers"

From: Vernon Schryver <[email-masked]>
Date: Mon, 24 Jul 2000 08:01:49 -0600 (MDT)

> From: Reiner Ludwig <[email-masked]>

> ...
> The designers of wireless link layers could make transmission across the 
> air much more efficient if they knew what kind of flow they were dealing 
> with, i.e., which QoS requirements the application on top has.
>
> Unfortunately, many wireless link layers today are one-size-fits-all and 
> that can be very inefficient, causing reduced e2e performance and waste of 
> radio resources (spectrum, battery power). The only escape from that - 
> given that we cannot use the TOS byte -...

Why can't wireless links use the RFC 1349 values?  Aren't those
4 values  supposed to be grandfathered?

Why can't you trust that people who aren't stupid will configure their
routers to translate the DS values they use inside their networks to mean
low-delay or high throughput back to 0x10 and 0x08 as packets leave their
networks?

Vernon Schryver    [email-masked]

---

From: Reiner Ludwig <[email-masked]>
Date: Tue, 25 Jul 2000 08:19:36 +0200

>4 values  supposed to be grandfathered?

As mentioned a number of times before: RFC1349 is obsoleted by RFC2474, 
even if BSD still uses it.

>low-delay or high throughput back to 0x10 and 0x08 as packets leave their

Somebody with a "gold card subscription" from her/his ISP will have the 
same DSCP on all of her/his flows independent of whether its ftp, telnet, 
or streaming media. So the last-hop router at the wireless link would have 
a hard time figuring out the right TOS values.

I assume that DSCPs will often have little to do with application layer QoS 
requirements but much more with how much you are willing to pay for your 
traffic.

///Reiner