diff --git a/draft-ietf-core-dns-over-coap.md b/draft-ietf-core-dns-over-coap.md index 49a73b7..216ab4f 100644 --- a/draft-ietf-core-dns-over-coap.md +++ b/draft-ietf-core-dns-over-coap.md @@ -94,6 +94,13 @@ The application use case of DoC is inspired by DNS over HTTPS {{-doh}} (DoH). DoC, however, aims for the deployment in the constrained Internet of Things (IoT), which usually conflicts with the requirements introduced by HTTPS. +Constrained IoT devices may be restricted in memory, power consumption, +link layer frame sizes, throughput, and latency. They may +only have a handful kilobyte of both RAM and ROM. They may sleep for long +durations of time, after which they need to refresh the named resources they +know about. Name resolution in such scenaries must take into account link +layer frame sizes of only a few hundred bytes, bit rates in the magnitute +of kBit/s, and latencies of several seconds {{-constr-nodes}}. To prevent TCP and HTTPS resource requirements, constrained IoT devices could use DNS over DTLS {{-dodtls}}. In contrast to DNS over DTLS, DoC