Hello, how is "send_arb" supposed to work, i.e. how to specify method-specific parameters (e.g. header fields) to it? E.g. call send_arb CANCEL sip:user at host works fine (without any supplemental parameters), but call send_arb SUBSCRIBE sip:user at host creates a non-conforming protocol request (lacking "Expires:" field). In particular, how to specify Expires: 0 for "send_arb SUBSCRIBE" for pjsua (running in "cli" mode)? Eeri Kask