|High availability model||Active-Standby||All appliances in the cluster are active.|
|Number of appliances in HA cluster||Always 2||2 to 100|
|Licensing model||Two separate appliance-based license files||CMS-based pooled user license obtained from the License Manager Service|
|Location of appliances||Appliances must be in a single data center less than 3 feet apart.||Globally distributed locations|
|SMA appliances supported|
All physical appliances.
Virtual appliances are notsupported.
|All SMA physical and virtual appliances are supported.|
|Virtual infrastructure||Not needed|
CMS is a virtual machine and must be hosted on virtual infrastructure (VMWare ESX/i, Microsoft Hyper-V, AWS, Azure, or KVM)
|Mix of appliances||Both appliances in the HA Pair must be identical (for example two SMA EX-7200s)||The cluster can have any combination of physical and virtual SMA appliances.|
|Release versions supported|
SMA 10.7.2 and 11.4.0
Not supported after 11.4.0 support expires
SMA 12.1 and higher
No plans to back port to 11.4
|End of Life||April 2019 (3 years after release of 11.4)||This is the next generation of SMA HA|
|Disaster Recovery||Not Supported. Appliances in an HA Pair must be in the same data center.|
Appliances in the cluster can be globally distributed.
|Redirection model||Uses a VIP|
Requires customers to configure DNS for Global Traffic Optimizer.
|Session restoration||Session is automatically restored on the paired appliance.||VPN reconnection and session restoration is supported with Global HA in SMA 12.4.|
Personal Bookmarks, Local User accounts, Device Registration.
Per-app VPN data persists across a failover.
User lock out persists across a failover.
|Personal bookmarks, Local User accounts, Device Registration, per-application VPN data, and user lockouts are supported with Global HA in SMA 12.4.|
|Single Points of Failure||HA Pair is installed in one datacenter which is susceptible to power, network or other disasters|
CMS server failure.
A CMS outage for a few minutes has little or no adverse affect on HA.
CMS is a virtual appliance and relies on the HA model of the IT department for it virtual infrastructure.
CMS has a relatively low MTTR if a full clone is instantiated or the HA Cluster model is used.
License Manager Service.
CMS queries the License Manager every 24 hours and continues to operate for 30 days without access to the License Manager.