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Re: [802.3_EPOC] 回复: Re: [802.3_EPOC] What is the problem with the EPoC converter, and what is the CLT?



Satish,

The acronym stands for Ethernet-over-Coax. This includes a family of technologies, many borrowed from home networking, that have found _expression_ in markets such as China where there is an abundance of MDUs and where cable runs tend to be short and unamplified.

Alex

On Mar 6, 2012, at 12:43 PM, "Mudugere, Satish" <satish.mudugere@xxxxxxxxx> wrote:

Hi Team,

I see another acronym EoC in this email. What is the significance of this acronym? Can you please throw some light on this?

-Satish

 

From: Eugene Dai [mailto:Eugene.Dai@xxxxxxx]
Sent: Sunday, March 04, 2012 10:37 AM
To: STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_EPOC]
回复: Re: [802.3_EPOC] What is the problem with the EPoC converter, and what is the CLT?

 

When relates EPON with “bridge” concept it becomes tricky. First of all, an EPON OLT does functions like a bridge between PON and external networks; but is not in the conversional way. An external bridge connected to an OLT would expect ONUs connected to the PON as a LAN, but it is not (in theory or in EPON standard)).   In EPON the logic connection between OLT and ONUs are multiple P2P links identified by LLIDs.  So in theory, a network port will see multi-LANs. In practice, an EPON appears as a LAN or multiple VLANs to an upper network port by the implementation of bridge functions at OLT.

 

So, a functional block (CMC, CLT, OCU, ECE etc.) between OLT and ONU/CNU is hardly to qualify as a bridge with the assumption of un-terminated EPON MAC flow. If we terminate EPON MAC, such as in the scenario that an EPON as a feeder network to an EoC network, the functional block between ONU and EoC could be a bridge or a switch.   

 

Thanks,

Eugene

 

From: 姚永 [mailto:yy0412@xxxxxxxxx]
Sent: Saturday, March 03, 2012 5:42 PM
To: STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
Subject: [802.3_EPOC]
回复: Re: [802.3_EPOC] What is the problem with the EPoC converter, and what is the CLT?

 

抱歉,我没有学,只好用中文答复。

应该是二层、也就是数据链路层(包括MAC)的设备,博通专利中的名称是CMC,意思是“Coaxial Media Converter”――物理层的转换。我的上一个邮件实际是对单纯物理层转换提出了疑问。但是我们希望MAC层不要分成两段――光和电各一段,也就是不希望当中有个桥接设备。在中国,EoC最初就是以缆桥命名的,其短板就是不能端到端。我们认为,解决的方案之一就是扩展EPON MPCP协议,在CMC(或者OCU、或者ECB,叫什么不重要)变换一下帧格式,也许还要增加一些预测帧,同时对数据存储转发,但是保持OLTCNU的控制、管理、调度

 

2012-03-04


姚永


发件人:Geoff Thompson

发送时间:2012-03-04 08:09

题:Re: [802.3_EPOC] What is the problem with the EPoC converter, and what is the CLT?

收件人:STDS-802-3-EPOC

抄送:

 

David-
As I discussed in my earlier message,
your statement below:

‘Bridge’ is actually the more generic term.

is not correct.
In IEEE 802, a "bridge" is not a generic term.
Rather, it is a specific type of device whose configuration in standardized in 802.1

Best regards,
    Geoff Thompson

On 23//12 11:42 PM, Barr, David wrote:

From: David Barr <David.Barr@xxxxxxxxxxxx>

Date: Fri, 2 Mar 2012 17:01:43 -0800
To: "Salinger, Jorge" <Jorge_Salinger@xxxxxxxxxxxxxxxxx>, EPoC Study Group <STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
Subject: RE: [802.3_EPOC] What is the problem with the EPoC converter, and what is the CLT?

 

Yes, I agree with Jorge, Valy, Satish & Mr. Yao (SARFT), that a Bridge makes more sense.

‘Media Converter’ implies a PHY-layer hub, which will not be optimum for coax.

MACs are just digital logic, which are fully exposed to Moore’s Law.

Why preserve the MAC, if it becomes a vanishingly small part of the solution?

Particularly when preserving the sub-optimum MAC ruins the economics on coax.

‘Bridge’ is actually the more generic term.

The advisable approach is to bridge to coax-optimized technology,

with IEEE focusing on specifying the manageability & provisioning across that bridge.

-Dave

 


 


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