UP                       CP
                 | CGN Address Allocation  |
                 |         Request         |
              1.1|-------- via Ci--------->|
                 | CGN Address Allocation  |
                 |         Response        |
              1.2|<------- via Ci----------|
                 |                         |
                 | CGN Address Renew       |
                 |         Request         |
              2.1|-------- via Ci--------->|
                 | CGN Address Renew       |
                 |         Response        |
              2.2|<------- via Ci----------|
                 |                         |
                 | CGN Address Release     |
                 |         Request         |
              3.1|-------- via Ci--------->|
                 | CGN Address Release     |
                 |         Response        |
              3.3|<------- via Ci----------|
                 |                         |