Field of the Invention
The present invention relates to a communication apparatus, a control method therefor, and a storage medium.
Description of the Related Art
Conventionally, in a company engaged in receiving orders using a G3 facsimile machine capable of connecting to a plurality of communication lines, it is sometimes the case that all the lines are occupied by fax transmission, disabling fax reception and obstructing the operation of receiving orders.
Thus, by specifying a transmit-disable setting on a line by line basis and using the line for which the transmit-disable setting has been specified in a receive-only mode, it has become possible to receive a fax anytime using the G3 facsimile machine, and consequently, operations are no longer obstructed.
Recently, an IP facsimile machine which uses an IP network and has a facsimile communications function compliant with SIP (Session Initiation Protocol) and T.38 has been coming into wide use by replacing the G3 facsimile machine. SIP is a call control protocol used in an IP network prescribed by RFC 3261 to conduct multimedia communications using various voices, data, images, and the like. On the other hand, T.38 is one of ITU-T recommendations and is a standard which prescribes a method for translating facsimile signals used in a subscriber telephone network into IP messages for use in communications.
Known examples of such an IP facsimile machine include one which has a multi-session function capable of conducting multiplexed communications using an IP network and can simultaneously process IP facsimile transmission and reception in multiplex mode using the IP network.
Whereas conventional G3 facsimile machines have a plurality of physical lines in order to connect to multiple lines and cannot conduct communications unless each of the physical lines has a phone number, the IP facsimile machine can perform simultaneous processing in multiplex mode, once connected to the IP network using a single physical network cable. Also, the IP facsimile machine can perform simultaneous processing using a single phone number.
As with the G3 facsimile machine, even the IP facsimile machine has a problem in that all sessions can be occupied by fax transmission, disabling fax reception.
To deal with this problem, a technique is known which allows a transmit-only session or receive-only session to be specified with respect to each communications session. With this technique, each session is set to be either a transmit-only session or a receive-only session in advance, and when there is a call-out request or call-in request, only fax transmission is assigned to the transmit-only session and only fax reception is assigned to the receive-only session with reference to the settings described above (see, for example, Japanese Laid-Open Patent Publication (Kokai) No. 2004-112515).
However, with the facsimile machine disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2004-112515, if, for example, two sessions are available and one of them is set to be transmit-only while the other is set to be receive-only, even if there is an inbound call when a fax is being received using the receive-only session, the other session is transmit-only, and naturally cannot be used for fax reception.
In a business engaged in receiving orders using facsimile, since calls are received frequently, one wants to use both sessions for fax reception, but there is a problem in that if both sessions are set to be receive-only, fax transmission is disabled completely.