Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: [802.3ae] Clause 46.3.1.4 Draft 3.1




Jacob,

In my understanding, it should be Idle shrinkage and not preamble shrinkage
which should be used to do rate control.

Regards,

Devendra Tripathi
CoVisible Solutions, Inc
(formerly VidyaWeb Inc)
90 Great Oaks Blvd #206
San Jose, Ca 95119
Tel: (408)226-6800,
Fax: (408)226-6862

> -----Original Message-----
> From: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
> [mailto:owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx]On Behalf Of jacob
> Sent: Tuesday, August 07, 2001 4:40 AM
> To: Julio.Hernandez@xxxxxx; THALER,PAT (A-Roseville,ex1);
> stds-802-3-hssg@xxxxxxxx
> Subject: [802.3ae] Clause 46.3.1.4 Draft 3.1
>
>
> Hello,
>
> Q1.
> >From Clause 46.3.1.4 Draft 3.1 Page 270 , line 4 and 5,
> it appears that the effective data rate control is achieved by dynamic
> preamble shrinkage (i.e either one or two
> 32bit columns of preamble before start of  ethernet destination
> address-as shown below)
>
>  I column             II Column         III Column
>    SOF                PRMBL               DA
>    PRMBL              PRMBL               DA
>    PRMBL              PRMBL               DA
>    PRMBL              SFD                 DA
> or
>  I column            II Column
>    SOF               DA
>    PRMBL             DA
>    PRMBL             DA
>    SFD               DA
>
> In draft 3.0 Clause 46.3.1.4 Draft 3.0 Page 251 , line 37and 38,
> it appears that the effective data rate control is by dynamic addition
> and deletion of IPG columns in between
> ethernet frames(i.e the IPG columns will dynamically change to say 2 or
> 4 cloumns for a nominal 3 IPG
> colmun(96bits).
>
> Q2.
> Is it mandatory to support effective data rate control only by dynamic
> preamble column shrinkage?
>
> Q3
> Is it right to consider /T/ (End of Frame Character)as IPG octect?
> (Minimum 5 octects IPG infers- one 32 bit column of IDLE and an octect
> of /T/ ; refer 46.2.1 line 53)
>
> Please clarify the observations and comment on the same.
>
>
> regards
> jacob
>