pub fn purr(uri: &Uri) -> Option<&[u8]>Expand description
The PURR a URI carries, if it carries one (§8.7).
Returned raw and not interpreted. The PURR is the proxy’s name for a binding, so that a
mid-dialog request can be matched to the binding it belongs to without re-deriving it from the
pn-* values — which means it is only useful to a party that stores bindings. sipx stores
none: it is a user agent, not a registrar or a proxy, so it reads the PURR its registrar
assigned (see Indicators::purr), carries it, and does no matching with it. That half of
§5.6 belongs where the other proxy roles do.