Cisco Cisco Customer Voice Portal 8.0(1) Design Guide
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Cisco Unified Customer Voice Portal (CVP) 8.x Solution Reference Network Design (SRND)
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Chapter 4 Designing Unified CVP for High Availability
Server Groups
Server Group Heartbeat Settings
The Server Group heartbeat default setting sets the ping up/down interval between any two pings; it is
not the setting between pings to the same endpoint. The Server Group does not wake up at a specific
interval and ping all elements because this approach would introduce a seesaw effect on CPU usage.
Also, it takes more resources when the system has to ping many end points. For example, for 3 total
elements across all groups, to proactively ping each element at 30 second intervals, you have to set the
ping interval at 10 seconds.
not the setting between pings to the same endpoint. The Server Group does not wake up at a specific
interval and ping all elements because this approach would introduce a seesaw effect on CPU usage.
Also, it takes more resources when the system has to ping many end points. For example, for 3 total
elements across all groups, to proactively ping each element at 30 second intervals, you have to set the
ping interval at 10 seconds.
It is less deterministic for reactive mode since elements that are currently down can fluctuate so the ping
interval fluctuates with it.
interval fluctuates with it.
Note
•
Heartbeat Behavior Settings for Server Groups. To turn off pinging when the element is up, set
Up Endpoint Heartbeat Interval to zero (reactive pinging). To turn off pinging when the element is
down, set the Down Endpoint Heartbeat Interval to zero (proactive pinging). To ping when the
element is either up or down, set the heartbeat intervals to greater than zero (adaptive pinging).
Up Endpoint Heartbeat Interval to zero (reactive pinging). To turn off pinging when the element is
down, set the Down Endpoint Heartbeat Interval to zero (proactive pinging). To ping when the
element is either up or down, set the heartbeat intervals to greater than zero (adaptive pinging).
•
Heartbeat Response Handling. Any endpoint that CVP may route calls to should respond to
OPTIONS with some response, either a 200 OK or some other response. Any response to a heartbeat
will indicate the other side is alive and reachable. A 200 OK is usually returned, but proxy servers
like the Cisco Unified Presence Server (CUP Server) or Cisco Unified SIP Proxy Server (CUSP
Server) may return a 483 Too Many Hops response, since the max-forwards header is set to zero in
an OPTIONS message. Sometimes the endpoints may not allow OPTIONS or PING, and may return
405 Method Not Allowed, which is fine as well.
OPTIONS with some response, either a 200 OK or some other response. Any response to a heartbeat
will indicate the other side is alive and reachable. A 200 OK is usually returned, but proxy servers
like the Cisco Unified Presence Server (CUP Server) or Cisco Unified SIP Proxy Server (CUSP
Server) may return a 483 Too Many Hops response, since the max-forwards header is set to zero in
an OPTIONS message. Sometimes the endpoints may not allow OPTIONS or PING, and may return
405 Method Not Allowed, which is fine as well.
By default, Server Group heartbeats are performed using a UDP socket connection. The transport type
can be changed to TCP from the Operations Console Server Groups window.
can be changed to TCP from the Operations Console Server Groups window.
Whenever an element has an unreachable or overloaded status, that element is marked as being down
completely, that is for both UDP and TCP transports. When the element is up again, it is allowed to be
routable for both UDP and TCP.
completely, that is for both UDP and TCP transports. When the element is up again, it is allowed to be
routable for both UDP and TCP.
Note
TLS transport is not supported.
Duplicate Server Group Elements are excluded for heartbeating since the heartbeating is already
established for that element.
established for that element.
Note
Refer to the Configuration and Administration Guide for Cisco Unified Customer Voice Portal for
typical configurations for the Server Groups feature. Document available at:
typical configurations for the Server Groups feature. Document available at:
Static Routes Validation
The hostname or IP address of a static route is validated at startup and configuration deployment time
with a DNS lookup resolution. If the hostname does not resolve to an A record or an SRV record, then
the route is disabled and a notice is printed in the Unified CVP error log. The calls will not be routable
to this route in this state. If the host is in the local SRV Server Groups configuration as an SRV name,
then the host will not undergo this check, because it resolves to a local SRV name. IP addresses always
pass this validation.
with a DNS lookup resolution. If the hostname does not resolve to an A record or an SRV record, then
the route is disabled and a notice is printed in the Unified CVP error log. The calls will not be routable
to this route in this state. If the host is in the local SRV Server Groups configuration as an SRV name,
then the host will not undergo this check, because it resolves to a local SRV name. IP addresses always
pass this validation.