Re: [Netconf] request for comments on draft-ietf-netconf-udp-pub-channel

Hi Tianran,

I have read this document. In general, it's in good shape and useful. 
Here I have some comments:

1. Section 1, the "Introduction" mentions: "Firstly, data collector will
suffer a lot of TCP connections from, for example, many line cards equipped
on different devices." and follows "the centralized design requires data to
be internally forwarded from those line cards to the push server, presumably
on a main board, which then combines the individual data items into a single
consolidated stream."
I agree with the later point. And if so, why do you think the first point is
sustained, i.e., the data collector should not be the bottle neck.
> 
2. Section 3, the "Solution Overview" mentions: "The Component Subscriptions
are distributed to the Agents. Subsequently, each data originator generates
its own stream of telemetry data, collecting and encapsulating the packets
per the Component Subscription and streaming them to the designated
Receivers."
Does the line card store data with consistent format follows the YANG
schema? Otherwise how to achieve the mechanism that described by this
document?

3. Section 4.2 "Configured Subscription" says "The first message MUST be a
separate subscription-started notification to indicate the Receiver that the
pushing is started. Then, the notifications can be sent immediately without
any wait."
But you did not explain why this is "MUST". It seems not obviously
necessary.

4. Section 5.2, in "Data Format of the Message Header", is a line cards ID
necessary? So that the receiver know where the data is from. This may be
useful when a line card has problem and wrongly send a lot of data.

5. Section 5.3.1., why "Reliability Option" is necessary. If I need a
reliable transport, why not just use a TCP based channel? Then all the
retransmission, congestion control are solved. And if "Reliable Streaming
Mode" is enabled, the line card need to maintain the state, which loss the
simple merit of UDP.

6. I do not quite understand the example showed in section 5.3.1. Is there
any problem on the received ID? Which is the Message ID and which is the
previous ID? Why Message ID 9 is not received by B? ...

Best Regards.

Aijun Wang
Network R&D and Operation Support Department
China Telecom Corporation Limited Beijing Research Institute,Beijing, China.

> -----Original Message-----
> From: Netconf [mailto:netconf-bounces@ietf.org] On Behalf Of Tianran 
> Zhou
> Sent: Thursday, June 07, 2018 10:03 AM
> To: netconf@ietf.org
> Subject: [Netconf] request for comments on 
> draft-ietf-netconf-udp-pub-channel
> 
> Hi WG,
> 
> We've got some comments on the UDP based Publication Channel for 
> Streaming Telemetry. And we are going to update it, specifically on the
security aspect.
> https://datatracker.ietf.org/doc/draft-ietf-netconf-udp-pub-channel/
> 
> Could you please help to review?
> Any comment is appreciated.
> 
> Thanks,
> Tianran
> 
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