Re: [16NG] Re: traffic classification

["yw_chen" <[e-mail]>]

Dear All,

I am Yen-Wen Chen from Dept. of Communication Engineering, National Central 
University, Taiwan. As I know that the classifier in 802.16 is applied to 
match the network layer traffic (e.g. IP packets or IPv6 packets) into MAC 
flows of 802.16. Each MAC flow has a connection ID (CID) and is associated 
with a specific forwarding class (e.g. UGS, rtPS, nrtPS, ertPS, or best 
effort) and QoS-related parameters (e.g. delay time, loss rate, etc.). The 
mapping rules does not specify in the spec. and is decided in accordance 
with different applications. Packets with different IP Headers may be mapped 
to the same CID if those packets are with the same treatment in the link 
layer of 802.16.

Yen-Wen






On Thu, 1 Feb 2007 00:37:21 +0900, JinHyeock Choi wrote
> > > I think it _may_ be relevant here.  IPv6 has a Traffic Class field with
> > > defined values (see rfc2474 for 6bit DSCP, and rfc2597 for AF Assured
> > > Forwarding values).  802.16 has Service Class service flow encodings
> > > (11.13.4 in 802.16-1004).  The mapping between the two should be
> > > specified here I believe.
> > >
> > > Basically one would need to define mappings between DSCPs and 802.16
> > > Service Flow encodings.  Remark the mapping is not straightforward
> > > because DSCP uses 6bit while service field is on 4bit.  But not all
> > > values from 6bit need to be encoded either.
> > >
> > > I think 802.16 spec doesn't define these mappings.  Although they do
> > > define filter in the CS that interprets the IPv6 Traffic Class field.
> >
> > Anyone who understands in detail what 802.16 classification
> > does, feel free to jump in here... DJ?
> >
> > My assumption was that 802.16 defines a classification mechanism
> > that can look at certain fields from IP packets and determine what
> > service flow should be used, including all parameters used in the
> > service flow. If this is not the case then you are right.
> 
> Classification is the process by which a MAC SDU (IPv6 packet in our
> case) is mapped onto a particular transport connection for
> transmission between MAC peers (BS and MS in our case). The mapping
> process associates an IPv6 packet with a transport connection and its
> CID (Connection Identifier).
> 
> Classifiers are matching criteria applied to each packet and consist
> of some protocol-specific packet matching criteria such as 
> destination IP address. If a packet matches the specified packet 
> matching criteria
> (i.e. classifier(s)), it is then delivered to the SAP for delivery 
> on the connection defined by the CID (Connection Identifier).
> 
> You may find more detail in 5.2.2 of 802.16. I also put a figure in
> 
> http://www.diffeo.com/16ng/fig.gif
> 
> Thanks for your kind consideration.
> 
> Best Regards
> 
> JinHyeock
> 
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