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

RE: RE: structure agnostic transport and a start of a frame



Hi Liquan,

 

Okay.. defining full blown fragmentation support into RoE was not what I had in mind originally. If people see need for it, then we probably need to do it. Following on that path we most likely also need to able to indicate that the RoE has “no idea of upper layer framing”. So with “start, mid and end frame” information that would fit into two bits field.

 

- Jouni

 

From: yuan.liquan@xxxxxxxxxx [mailto:yuan.liquan@xxxxxxxxxx]
Sent: Sunday, May 10, 2015 10:35 PM
To: Jouni Korhonen
Cc: stds-1904-3-tf@xxxxxxxx; STDS-1904-3-TF@xxxxxxxxxxxxxxxxx; stds-1904-3-tf@xxxxxxxx
Subject:
答复: RE: structure agnostic transport and a start of a frame

 

Hi Jouni,
Assuming upper layer data(like CPRI super frame), the size of package is larger than RoE package, the upper layer data will map to several RoE frames, so we need to know which is the start of package(SoP), the reciever may has no information how many RoE frames are needed for one upper layer data package, then the end of package(EoP) is needed, if the bits of EoP/SoP is false, the this frame is normal.

This kind of idea is used by other mapper map a varied upper layer package to lower layer frames, for example, in DSL bonding system. we can consider whether this idea is used for RoE mapper.

BR.
Liquan, ZTE Corp.




发件人:         Jouni Korhonen <jouni.korhonen@xxxxxxxxxxxx>
收件人:         "yuan.liquan@xxxxxxxxxx" <yuan.liquan@xxxxxxxxxx>,
抄送:        "stds-1904-3-tf@xxxxxxxx" <stds-1904-3-tf@xxxxxxxx>, "STDS-1904-3-TF@xxxxxxxxxxxxxxxxx" <STDS-1904-3-TF@xxxxxxxxxxxxxxxxx>
日期:         2015/05/09 04:12
主题:        RE: structure agnostic transport and a start of a frame
发件人:        stds-1904-3-tf@xxxxxxxx





Hi,
 
How would an “end marker” help here in that case? Or are you suggesting that we should be able to figure out “first fragment”, “normal fragment” and the “last fragment” of the structure agnostic payload?  Because that is what you essentially get with separate start & end flags..
 
- jouni
 
From: yuan.liquan@xxxxxxxxxx [mailto:yuan.liquan@xxxxxxxxxx]
Sent:
Wednesday, May 06, 2015 6:08 PM
To:
Jouni Korhonen
Cc:
stds-1904-3-tf@xxxxxxxx; STDS-1904-3-TF@xxxxxxxxxxxxxxxxx
Subject:
答复: structure agnostic transport and a start of a frame
 
Jouni,
There may be some varied types of upper layer data carried over RoE frame, so the size is also varied, which RoE frame is the first part of upper layer data package and which RoE frame is the end of upper layer data package should be indicated, then 1 more bit may be needed.


BR.

Liquan

ZTE CORP.




发件人:         Jouni Korhonen <jouni.korhonen@xxxxxxxxxxxx>
收件人:         "STDS-1904-3-TF@xxxxxxxxxxxxxxxxx" <STDS-1904-3-TF@xxxxxxxxxxxxxxxxx>,
日期:         2015/05/07 00:41
主题:        structure agnostic transport and a start of a frame
发件人:        stds-1904-3-tf@xxxxxxxx






Folks,

Kevin brought up an interesting point a while back. If we want a truly structure agnostic transport mode be supported that would imply just a stream of bits. For example, in a case of CPRI we would not even touch 8B/10B or 64B/66B coding to preserve e.g. K-characters etc. I am fine with this (with some pain). However, it could be beneficial to indicate the start of a frame in the RoE header (1 bit flag). The assumption I have is that all data streams to be carried over RoE in structure agnostic mode still have some kind of framing. As an example we could indicate the start of each hyper frame in a case of CPRI.

The same flag would also serve structure aware modes & native RoE flows. Just to indicate when some packet is a start of a radio frame or other framing..

This is a small optimization that may or may not be worth it.. Comments/thoughts?

- Jouni

--
Jouni Korhonen, CTO Office, Networking, Broadcom Corporation
O: +1-408-922-8135,  M: +1-408-391-7160