Cisco Cisco Expressway Maintenance Manual
primary. Any configuration changes made to the primary peer are then automatically replicated across all the other
peers in the cluster.
peers in the cluster.
You should only make configuration changes on the primary Expressway.
Caution:
Do not adjust any cluster-wide configuration until the cluster is stable with all peers running. Cluster
database replication will be negatively impacted if any peers are upgrading, restarting, or out of service when
you change the cluster's configuration.
you change the cluster's configuration.
Any changes made on other peers are not reflected across the cluster, and will be overwritten the next time the
primary’s configuration is replicated across the peers. The only exceptions to this are some
primary’s configuration is replicated across the peers. The only exceptions to this are some
.
You may need to wait up to one minute before changes are updated across all peers in the cluster.
Secure communication between peers
The Expressway uses TLS (Transport Layer Security) to secure the communications between cluster peers. Peers
identify each other using certificates; if you wish to enforce TLS verification, a Expressway must have a certificate
that is trusted by all other peers, or it will be unable to join the cluster.
identify each other using certificates; if you wish to enforce TLS verification, a Expressway must have a certificate
that is trusted by all other peers, or it will be unable to join the cluster.
License Usage Within a Cluster
The following types of licenses are pooled for use by any peer in a cluster, irrespective of which peer the licenses are
installed on:
installed on:
■
Rich media session licenses
■
TURN relay licenses
You can cluster up to 6 Expressway systems to increase capacity by a maximum factor of 4.
If a cluster peer becomes unavailable, the shareable licenses installed on that peer remain available to the rest of the
cluster peers for two weeks from the time the cluster lost contact with the peer. This will maintain the overall license
capacity of the cluster — however, note that each peer is limited by its physical capacity. After this two week period,
the licenses associated with the unavailable peer are removed from the cluster. To maintain the same capacity for
your cluster, you should ensure that either the problem with the peer is resolved or new option keys are installed on
another peer in the cluster.
cluster peers for two weeks from the time the cluster lost contact with the peer. This will maintain the overall license
capacity of the cluster — however, note that each peer is limited by its physical capacity. After this two week period,
the licenses associated with the unavailable peer are removed from the cluster. To maintain the same capacity for
your cluster, you should ensure that either the problem with the peer is resolved or new option keys are installed on
another peer in the cluster.
Small / Medium / CE500 /
CE1100
‡
systems
Large / CE1000 / CE1100
‡
systems
Rich media sessions
150
†
500
Room / Desktop system
registrations
registrations
2500
5000
TURN relays *
1800
6000
Table 13 Maximum licenses that a peer can use
‡ CE1100 appliance can run with medium or large capacity, depending on whether it has 1Gbps or 10Gbps NICs
installed.
installed.
† This is the maximum number of licenses the system can use. This limit specifically applies to the case where a peer
becomes unavailable and the other peers must use that peer's licenses to honor the cluster's overall capacity. This is
not intended as a production capacity limit, only as a temporary measure to allow the affected peer to be returned to
normal service. We strongly discourage installing more than 100 licenses on any platform that has small or
medium capacity.
becomes unavailable and the other peers must use that peer's licenses to honor the cluster's overall capacity. This is
not intended as a production capacity limit, only as a temporary measure to allow the affected peer to be returned to
normal service. We strongly discourage installing more than 100 licenses on any platform that has small or
medium capacity.
* On a Large system, the total TURN capacity of 6000 relays is spread evenly across 6 ports; each port is limited to
handling 1000 relays. On a Small/Medium system, there is a single TURN port that handles up to 1800 relays.
handling 1000 relays. On a Small/Medium system, there is a single TURN port that handles up to 1800 relays.
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Cisco Expressway Administrator Guide
Clustering and Peers