MUC's design generally assumes a highly reliable network providing plenty of bandwidth, and it functions well in Internet settings. It is sometimes the case that server to server traffic is heavily constrained, with typical problems for constrained links being high latency, tiny amounts of available bandwidth and unreliability (including, potentially, long-term failure of S2S links). This document provides methods for allowing experiences close to those of standard MUC use while operating across such constrained links by allowing rooms to federate with remote counterparts and for users to connect to the federated MUC node nearest to them on the network for a given FMUC room. It requires no setup in advance, and needs no bandwidth for remote rooms without local occupants. The premise is that a proxy room joins another room and receives stanzas from the MUC just as another occupant would; this is analogous to the client to server model, whereby a client would connect to their local server and the server deals with connections elsewhere - the client joins a local room and the room deals with connections to other federated rooms.