Liquan,
I concur.
Our worst-case scenario will be streaming traffic without any compression, right?
To encapsulate 9.8304 Gbps traffic within a 10 Gbps link (including Ethernet overhead), you’ll probably need to be somewhere in the 1500-2000 bits of CPRI data put into an
Ethernet frame at a minimum. Having some extra bytes in the header for packets this large will have negligible impact on the throughput. I’m not suggesting we waste bytes, but the header impact for Ethernet frames >150 bytes is not as significant as one
might think. If going with larger packets (such as 500 bytes), the impact is even less.
--kb
===================================================================
From: stds-1904-3-tf@xxxxxxxx [mailto:stds-1904-3-tf@xxxxxxxx]
On Behalf Of 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