Re: MPE Question

[nurul <azila@nrg.cs.usm.my>]

ahhh.. i see...

thank you to you too, sir.

regards, 
nurul

On Thu, 2005-04-28 at 16:04, Bernhard Collini-Nocker wrote:
> Well, section packing is allowed, and MPE uses sections, so it can "ride 
> that horse". And, of course, MPE with section packing meanwhile is 
> supported by nearly all IRD cards and drivers. However, it is badly 
> described compared to ULE.
> 
> Regards,
> Bernhard
> 
> nurul wrote:
> > Hi,
> > 
> > Do MPE allows packing? cause as far as i concern it's only allow padding
> > while ULE allows both. Correct me if i'm wrong.
> > 
> > regards,
> > nurul
> > 
> > On Thu, 2005-04-28 at 13:22, Bernhard Collini-Nocker wrote:
> > 
> >>Siva Veerepalli wrote:
> >>
> >>>A couple of questions about MPE-FEC framing.
> >>>
> >>>1. The interim IP datacast standard A079 (meant to
> >>>facilitate DVB-H trials) specifies that only one
> >>>datagram should be used per MPE section i.e., no
> >>>fragmentation of IP datagram over multiple MPE
> >>>sections. However, the DVB Databroadcast specification
> >>>allows fragmentation of the IP datagram over multiple
> >>>sections. Does anyone know what the usual practice is?
> >>
> >>In order to reduce encapsulation overhead, section packing is used, i.e. 
> >>if the (remainder of an) IP packet does not fit exactly in a TS packet a 
> >>subsequent IP packet may start in that TS packet as well.
> >>In order to reduce jitter and latency, section packing is not used.
> >>
> >>You can find both on existing services.
> >>
> >>
> >>>Do the final DVB/IP datacast standards specify this
> >>>for DVB-H?
> >>
> >>The difficulty with section peckaing on the transmit side is that the 
> >>encapsulator needs to wait for subsequent IP packets to fill an 
> >>partially filled TS packet and therefor has typically a time-out 
> >>associated to that waiting, ie before flushing the buffer and 
> >>transmitting the final TS packet.
> >>
> >>
> >>>2. The MPE section has optional stuffing bytes at the
> >>>end of the section. Are these used? If yes, for what?
> >>
> >>Whenver an IP packets leaves "enough" space in the last TS packet 
> >>another IP packet could be inserted. If not wanted or needed, stuffing 
> >>takes care that the empty space is filled up with pattern 0xFF.
> >>
> >>
> >>>thanks,
> >>>Siva
> >>>
> >>>
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> >>
> > 
>