A subzone is a logical grouping of endpoints within a zone that allows the Expressway to apply different policies and bandwidth controls to different sets of endpoints1.
An endpoint is a device that can make or receive calls, such as a video conferencing system, a phone, or a soft client2.
When an endpoint registers with the Expressway, it is assigned to a subzone based on the following criteria3:
If the endpoint is making a traversal call (a call that crosses a firewall or a network boundary), it is assigned to the traversal subzone. A traversal call requires a traversal client zone on the Expressway that initiates the call and a traversal server zone on the Expressway that receives the call.
If the endpoint is not making a traversal call, it is assigned to a subzone based on the subzone membership rules. These rules specify the range of IP addresses or alias pattern matches for each subzone. If an endpoint’s IP address or alias does not match any of the membership rules, it is assigned to the default subzone.
If the endpoint is not allowed to register with the Expressway, it is rejected based on the registration restriction rules. These rules specify the IP addresses or aliases of the endpoints that are denied or allowed to register with the Expressway.
Therefore, the two statements that are true about the assignment of endpoints to a subzone are:
A. A registration restriction rule must be configured that matches the endpoint’s alias or IP subnet. This statement is true because the registration restriction rules are used to filter out the endpoints that are not allowed to register with the Expressway based on their alias or IP subnet3.
E. A subzone membership rule must be configured that matches the endpoint’s alias or IP subnet. This statement is true because the subzone membership rules are used to assign the endpoints that are allowed to register with the Expressway to the appropriate subzone based on their alias or IP subnet3.
The other options are incorrect because:
B. Endpoints making a traversal call must be registered to the traversal subzone. This statement is false because the traversal subzone is not a subzone that endpoints can register to, but a subzone that endpoints are assigned to when they make a traversal call3.
C. By default, all endpoints are registered to the default subzone. This statement is false because not all endpoints are registered to the default subzone, only those that do not match any subzone membership rules or make a traversal call3.
D. By default, all endpoints are registered to the neighbor subzone. This statement is false because the neighbor subzone is not a subzone that endpoints can register to, but a subzone that represents a neighbor zone (a logical connection to another Expressway or a third-party device) on the Expressway.
References := 1: Cisco Expressway Administrator Guide (X14.0) 2: Cisco Expressway Basic Configuration Deployment Guide (X8.11) 3: Cisco Expressway Administrator Guide (X14.0) : Cisco Expressway Administrator Guide (X14.0) : Cisco Expressway Administrator Guide (X14.0)
