  Citizens develop Wireless Mesh Networks (WMN) in many areas as an alternative
or their only way for local interconnection and access to the Internet. This
access is often achieved through the use of several shared web proxy gateways.
These network infrastructures consist of heterogeneous technologies and combine
diverse routing protocols. Network-aware state-of-art proxy selection schemes
for WMNs do not work in this heterogeneous environment. We developed a
client-side gateway selection mechanism that optimizes the client-gateway
selection, agnostic to underlying infrastructure and protocols, requiring no
modification of proxies nor the underlying network. The choice is sensitive to
network congestion and proxy load, without requiring a minimum number of
participating nodes. Extended Vivaldi network coordinates are used to estimate
client-proxy network performance. The load of each proxy is estimated passively
by collecting the Time-to-First-Byte of HTTP requests, and shared across
clients. Our proposal was evaluated experimentally with clients and proxies
deployed in guifi.net, the largest community wireless network in the world. Our
selection mechanism avoids proxies with heavy load and slow internal network
paths, with overhead linear to the number of clients and proxies.
