This disclosure describes techniques to support language assistance services for communication between devices. Per techniques of this disclosure, language assistant capabilities are exchanged between participating devices during call setup. A call protocol such as session initiation protocol (SIP) is suitably modified to exchange language assistant parameters during call set up. The SIP header fields are extended to add a parameter to indicate language assistant capabilities by indicating a suitable language code. An INVITE request is transmitted from an originating device that includes a language identifier that indicates the language assistant capabilities of the originating device. A corresponding language identifier of the terminating device is requested. A language identifier for the terminating device is obtained from and transmitted to the originating device along with a RING message. When the call is answered at the terminating device, an updated language identifier may be provided along with an OK message
