If the value in the Ext Len field is greater than the number of digits in the Ext Code field, the system interprets the Ext Code as a block of digits. For example, if the value in the Ext Len field is 4 and the value in the Ext Code field is 11, the CESID serves extensions 1100 through 1199. The Ext Code [11] is for a DID block. Ext Code [126] might point a non-DID block to a nearby DID extension 5241666.
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