Subject: [core] draft-ietf-core-coap-06 Reliability

From: Cullen Jennings <[email-masked]>
Date: Wed, 4 May 2011 20:42:40 -0600

A response-timeout of 2 seconds it two slow for real time applications. Imagine I have a light controlled by a light switch. If I hit the switch, and the initial packet is lost, then the sends packets happens 2 seconds later, the user is going to hate that system. It's too slow. A number like 200 ms would be more appropriate. 

The max retransmits of 4 may be too small for one particular scenario. Imagine a large number of devices that all connect to the same proxy. A power outage causes all of theses devices to simultaneously re register to the same proxy at the same time. Only have 4 retries per device could easily end up with many devices failing in use case like this. Moving from 4 to 6 would significantly improve the ability to deal with an avalanche restart. 

Cullen <in my role as an individual contributor>