# Frequently Asked Questions

## Correlation between JTAPI and TAPI CallID

**
JTAPI CallID calculation formula
**

JTAPI Calculates CallID using the below logic:- JTAPI Call Id = First 8 bits for CallManagerID and 24 bits for CallID -> ((callManagerID & 0x00ff) << 24) | (globalCallID & 0x00ffffff)

For example, if the CallManagerID= 1 (0x01) and the CallID=3884 (0x00000F2C), then using the above formula JTAPI CallID becomes 0x01000F2C which is 16781100 in decimal.

**
TAPI CallID calculation formula
**

TAPI Calculates CallID using the below logic:- TAPI CALLID = First 10 bits for CallManagerID and 22 bits for CallID -> ((callManagerID & 0x03ff) << 22) | (globalCallID & 0x003fffff)

For example, if the CallManagerID= 1 (0x01) and the CallID= 0x00000F2C, then using the above formula TAPI CallID becomes 0x00400F2C.

From this we can find, TAPI CallID is different from that of JTAPI CallID.

More info:- JTAPI exposes two interfaces that expose call id. However the integer value of call id exposed by JTAPI already is deprecated in 8.0. So from 8.0 onwards, JTAPI application should use non-integer interface to obtain call id, and TAPI app should use new info in LineCallInfo::DevSpecific which exposes both CallManagerID and CallID. However the old interface is deprecated but not removed yet. If the developers want, they still can use the above formulas to correlate call ids for pre-8.0 CUCM releases. The deprecation only applies to 8.0 and onwards.

## Determining the jtapi.jar version

To find out the version of the jtapi.jar file, set the jtapi.jar classpath and then type
**
java CiscoJtapiVersion
**
in command prompt.