I can't get the entire results of particular function like listPhone or getConferenceBridge, as it requires to provide particular search through searchCriteria.
Could anyone propose a solution for that except directly querying the database?
service.listPhone() ## gives error, because it's missing the filters.
Schema ref : Schema Ref documentation
The values for the search criteria elements are evaluated as SQL LIKE statements, meaning you can use wildcards, for example '%' which means 'match anything':
CUCM uses an Informix DB under the covers: https://www.ibm.com/support/knowledgecenter/en/SSGU8G_12.1.0/com.ibm.sqls.doc/ids_sqs_1388.htm
Note, you will want to take care when executing a 'retrieve all' request like this, as you could return huge data sets on large clusters. AXL data set size throttling may kick in: https://developer.cisco.com/docs/axl/#!axl-developer-guide/data-throttling-and-performance