digraph { rankdir=LR; subgraph cluster_0 { label="Data Center"; SIM [shape=rect]; Reader [shape=rect]; bankd [label="remsim-bankd"]; } subgraph cluster_1 { label="Remote Site"; client [label="remsim-client"]; SIMtrace [label="SIMtrace2\nAPP=cardem",shape=rect]; Phone [label="Phone/Modem",shape=rect]; } SIM -> Reader [label="ISO-7816-2/3",dir=both]; Reader -> bankd [label="USB CCID",dir=both]; bankd -> client [label="RSPRO/IPA/TCP/IP",dir=both]; client -> SIMtrace [label="USB",dir=both]; SIMtrace -> Phone [label="ISO-7816-2/3",dir=both]; }