The ITL verifies transactions proposed by registries to ensure they are consistent with rules agreed under
the Kyoto Protocol. Each registry sends transaction proposals to the ITL, which checks each proposal and
returns to the registry its approval or rejection. Once approved, registries complete the transaction.
In the event that a transaction is rejected, the ITL sends a code indicating which ITL check has been failed
and the registry terminates the transaction.
Data Exchange Standard (6517 kB) (DES) coordinate the functions of systems when processing transactions.
They define technical requirements for the communication between the ITL and registries. They also
define the checks performed by the ITL, embodying the policy rules agreed by Parties for the accounting
of their assigned amounts and their use of the Kyoto mechanisms.
Each registry is to be connected to the ITL through secure communication channels established across the
Internet. These connections will allow a registry to receive an immediate response from the ITL, typically
within a matter seconds after sending the transaction information.
The administrator of the ITL is the UNFCCC secretariat, which has awarded a contract for the development and
operation of the ITL to leading companies in the field of IT services. The ITL is hosted at two
commercially-operated data centres, one for primary operations and the other as a backup site, both located
in the United Kingdom. A service desk, also based in the United Kingdom, has been put in place to support the
administrators of the ITL, registries and the CITL.