Comment 2 for bug 1657091

@Michael Johnson
Hi， michael. Thanks for comments here.

1.As for IOT，the most part of the protocols used by services/app is based on udp. Such as CoAP （Constrained Application Protocol), DDS（Data Distribution Service for Real-Time Systems.
IOT need the capbility of real-time, large scaled data prosession...But it doesn't care about the reliable transmission.
So the udp in L4 is the right one.
CoAP protocol works for wire-less IOT cases.
DDS is based on the publish-subscribe model, and it is good to apply to the IOT view which need the requirements about High-speed source data access in application layer, interests subcribtion and etc.

2.DNS protocol

3.video chatting: RUDP（Reliable User Datagram Protocol）, RTP(RealTime Protocol), UDT(UDP-based Data Transfer Protocol).

So our servers behind vip need the udp support for this view. Currently, LB API doesn't support the udp value into the protocol parameters. I think it must be the haproxy not support udp loadbalance.

Also, the real openstack product may support mutil-backend drivers, such as LVS , nginx and haproxy. So I think we could add the udp support API, then if the backend driver support udp, we can make some desciptions.