Scale and Performance

This section details the supported configurations and corresponding scale, as well as Geo-Redundancy and Round Trip Time (RTT) requirements.

Unified Node Deployments

Configuration	Number of Unified Nodes	Number of Web Proxy Nodes	Supported Scale (# Subscribers)	Geo-Redundancy (Y/N)
Single node cluster VOSS-4-UC	1	0	50,000	NA
Two-Node VOSS-4-UC Across Data Centers	2	1 [1]	50,000	Yes [2] (Active-Standby) If RTT <= 10ms
Multi-Node VOSS-4-UC Across Data Centers	4	2 [1]	500,000	Yes (Active-Active) If RTT <= 10ms
	6	2 [1]	500,000	Yes (Active-Standby)
Multi-Node VOSS-4-UC One Data Center	4	2 [1]	500,000	No

Modular Node Deployments

Configuration	Number of Modular Nodes	Number of Web Proxy Nodes	Supported Scale (# Subscribers)	Geo-Redundancy (Y/N)
Application VOSS-4-UC Across Data Centers	1-8 [3]	2 [1]	500,000	Yes (Active-Active) If RTT <= 10ms
	1	2 [1]	500,000	Yes (Active-Standby)
Modular Database VOSS-4-UC Across Data Centers	2	2 [1]	500,000	Yes If RTT <= 10ms
	1	2 [1]	500,000	Yes
Multi-Node VOSS-4-UC One Data Center	4	2 [1]	500,000	No
Modular Application VOSS-4-UC One Data Center	1-8 [3]	2 [1]	500,000	No
Modular Database VOSS-4-UC One Data Center	3	2 [1]	500,000	No

The supported configurations and scale are based on a standard profile for each subscriber, which includes the following:

• Two endpoints (physical phone and soft client) per subscriber.
• Voice Mail
• Extension Mobility (EM)
• Single Number Reach (SNR)
• IM and Presence

The scale limits are not enforced by the system, but exceeding the limits can result in significant performance degradation.

Below follows notes on the difference between Active and Standby nodes, to clarify the Geo-Redundancy options.

• A Node that can process transactions is termed as an Active Node.
• The Standby Node is powered on and running the VOSS-4-UC software, but cannot process transactions.

For RTT across different UC components, this should not exceed 400ms. RTT will impact the duration of a transaction, but only for the remote leg, in other words, performing an action on the remote device.

[1]	(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) Two web proxy nodes can be used. It may be omitted if an external load balancer is available.

[2]

With only two Unified nodes, with or without Web proxies, there is no High Availability. The database on the primary node is read/write, while the database on the secondary is read only. Only redundancy is available. If the primary node fails, a manual delete of the primary node on the secondary and a cluster provision will be needed. If the secondary node fails, it needs to be replaced. Refer to the topic on DR Failover and Recovery in a 2 Node Cluster in the Platform Guide.

[3]	(1, 2) Horizontal scaling of Application nodes allows for increased API performance and transaction throughput.