Small System Support

In order to support small customers and lab and trial deployments, the PCA application can scale down to run on a small hardware footprint. This section describes the smallest supported PCA DSR deployments.

A lab or trial system may not be required to support in-service maintenance or have any hardware redundancy whatsoever. In the smallest supported lab/trial PCA DSR, IPFE is not included because it does not make sense to distribute ingress connections when there is only one DA-MP server.

The NOAM and SOAM servers are also running in simplex mode, meaning that no redundancy exists. In addition, the NOAM and SOAM are virtualized on a single physical server to save hardware. The binding and session SBR servers are also running in simplex mode and is configured to host both the Policy Binding and Policy Session databases. A single DA-MP hosts all Diameter signaling. Signaling is not affected if one or both of the (virtual) OAM servers happens to fail.

The configuration of the smallest viable commercially deployable PCA DSR, illustrated in , has enough hardware redundancy to support in-service maintenance:

Two DA-MPs are required to survive server failures and maintenance. These DA-MPs should be engineered at 40% load since in a failure or maintenance situation, one Server will have to handle the load for both.
Both binding and session SBR Servers pairs use the Active/Standby redundancy model in order to support failures and maintenance.
The NOAM/SOAM Server pair uses the Active/Standby redundancy model in order to support failures and maintenance.
Both NOAM and SOAM are virtualized onto a single pair of physical servers. The NOAM instance is Active on one server and Standby on the other. The SOAM instance is Active on one server and Standby on the other.

Smallest Supported PCA Field Deployment

The smallest supported Mated Pair of PCA DSRs, illustrated in Figure 2, has the following characteristics:

The NOAM servers are deployed at Site 1 using Active/Standby redundancy.
The Site 1 SOAM servers are deployed at Site 1, virtualized on the same servers with the NOAM servers. They, however, use the Active/Standby/Spare redundancy model, with the Spare server deployed at Site 2 and virtualized on the same server with one of the Site 2 SOAM servers.
The Site 2 SOAM servers are deployed at Site 2 using the Active/Standby/Spare redundancy model. The Spare Site 2 SOAM server is virtualized at Site 1 on one of the servers already hosting an NOAM and a Site 1 SOAM server.
A Binding SBR triplet is deployed with two servers at Site 1 and one server at Site 2.
A Session SBR triplet is deployed with 1 server at Site 1 and two at Site 2
Two DA-MPs are deployed at each site to support server redundancy at each site.

Smallest Supported PCA Mated Pair

The smallest supported mated triplets of PCA DSRs, illustrated in , has the following characteristics:

The NOAM servers are deployed at Site 1 using Active/Standby redundancy.
The Site 1 SOAM server are deployed at Site 1, virtualized on the same servers with the NOAM servers. However, the use the Active/Standby/Spare/Spare redundancy model, with the spare server deployed at Site 2 and Site 3 and virtualized on the same server with one of the Site 2 SOAM servers.
The Site 2 (and Site 3) SOAM servers are deployed at Site 2 (and Site 3) using the Active/Standby/Spare/Spare redundancy model. The spare Site 2 SOAM server is virtualized at Site 1 on one of the servers already hosting an NOAM and a Site 1 SOAM server.
A binding SBR triplet is deployed with two servers at Site 1 and one server each at Site 2 and Site 2 respectively.
A session SBR triplet is deployed with two servers at Site 2 and one server each at Site 1 and Site 3 respectively.
Two DA-MP servers are deployed at each site to support server redundancy at each site.

Smallest Supported PCA Mated Triplets