Computer Telephony Interface/Integration (CTI) provides a connection between telephone systems and computers and allows them to take advantage of computer processing when managing phone calls.
Telephony Application Programming Interface (TAPI) which was developped originally by Microsoft, and Java Telephony Application Programming Interface (JTAPI) can interact with Call Manager using CTI Communication via the CTI Manager.
Cisco Unity Express (CUE) also communicates with Call Manager using JTAPI and with CTI Quick Buffer Encoding (CTI-QBE) protocol.
Call Manager uses port TCP/2748 and TCP/2789 for CTI/JTAPI Communications.
CTI Manager interfaces with applications and communicates with Call Manager via SDL (System Distribution Layer) so it relies on the Cisco Database Layer Monitor Service. CTI Manager operates separately from Call Manager, and it is possible to have more than one CTI Manager active across the cluster but ONLY ONE instance on any given server !
So a JTAPI or TAPI application can connect to several CTI Manager at the same time but can use only one of those connections at a time.
Attendant Console is an application which is interacting with the server application TCD ( Telephony Call Dispatcher) which will monitor the linestate of every devices.
Once this application installed and configured properly , the assistant is able to see the user line and related informations.
IPMA is an application for managers and assistants which permits to assistants to handle managers’ calls. There are 2 types of IPMA operations:
- Proxy-line support mode
- Shared-line support mode
Proxy-line is available since Call Manager version 3.3. In this mode , calls made to managers are intercepted and redirected to an assistant or target based on the call rules. A manager in this mode can have only one associated assistant. Also the configuration of this mode is more complex as it requires the use of 2 CSS, 3 partitions, translation patterns and route points.
Shared-line is available since Call Manager version 4.0 and permits that managers and assistants share a primary line ( and DN associated). So in this mode , no special configuration is required and has also the advantage that a manager can have up to 10 assistants
EM is the ability for a user who logs into a phone to retrieve all user profile characteristics as number , speed dialing, line appearance, calling priviliges(Partition/CSS), MWI and so on.
EM is enabled using XML-based services and relies on the Cisco Call Manager / Cisco Database Layer Monitor services and runs as a Tomcat web service in order to function.
Be careful as because the profile is specific to a device (phone) type, it will work only when user logs in to that specific type of device.
A MTP can bridge tohether two full-duplex voice stram and if necessary convert between G711 ulaw and alaw as well as different sample sizes. So as the MTP bridge is handling each stream independently, H.323 supplementary services can be supported. In other words, MTP will enhance H.323v1 with all these supplementary services(Call Park, Hold , Transfer , Conferencing,…).
Pay attention also that you can use MTP in order to provide the translation between the out-of-band DTMF tones used by SCCP and SIP in-band (payload type) DTMF tones.
Transcoders enable devices using different codecs to communicate by converting a voice stream using one codec into a voice stream using another codec.