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nortel

For my 5500's running v6.2.4 I found all the CPU information in this OID:
1.3.6.1.4.1.45.1.6.3.8.1.1

If you walk this OID you will see the options for last 10s, 1min etc for each of the units.

Here are the temp OID's:
1.3.6.1.4.1.45.1.6.3.7.1.1

If you need more info, Google nortel 5500 cpu oid