Cisco Cisco Expressway Maintenance Manual
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Each peer is using a hardware platform (appliance or virtual machine) with equivalent capabilities; for
example, you can cluster peers that are running on standard appliances with peers running on 2 core Medium
VMs, but you cannot cluster a peer running on a standard appliance with peers running on 8 core Large VMs.
example, you can cluster peers that are running on standard appliances with peers running on 2 core Medium
VMs, but you cannot cluster a peer running on a standard appliance with peers running on 8 core Large VMs.
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All peers have the same set of option keys installed:
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The number of call license keys may be different on different peers; all other license keys must be identical
on each peer.
on each peer.
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The Expressway must be restarted after installing some option keys in order to fully activate them.
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Each peer has a different system name.
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H.323 mode is enabled on each peer (Configuration > Protocols > H.323, and for H.323 mode select On).
The cluster uses H.323 signaling between peers to determine the best route for calls, even if all endpoints are
SIP endpoints.
SIP endpoints.
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The Expressway cluster has a DNS SRV record that defines all cluster peers.
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The DNS servers used by the Expressway peers must support both forward and reverse DNS lookups of all
Expressway peer addresses; the DNS servers must also provide address lookup for any other DNS functionality
required, such as:
Expressway peer addresses; the DNS servers must also provide address lookup for any other DNS functionality
required, such as:
—
NTP servers or the external manager if they configured using DNS names
—
Microsoft Lync Server FQDN lookup
—
LDAP server forward and reverse lookup (reverse lookups are frequently provided through PTR records).
Note that DNS server configuration is specific to each peer.
Then, to create your cluster you must first configure a master peer and then add the other peers into the cluster one-
by-one.
by-one.
You are recommended to backup your Expressway data before setting up a cluster.
.
Maintaining a Cluster
The Clustering page (System > Clustering) lists the IP addresses of all the peers in the cluster, to which this
Expressway belongs, and identifies the master peer.
Expressway belongs, and identifies the master peer.
Cluster name
The Cluster name is used to identify one cluster of Expressways from another. Set it to the fully qualified domain
name (FQDN) used in SRV records that address this Expressway cluster, for example
name (FQDN) used in SRV records that address this Expressway cluster, for example
cluster1.example.com
.
The FQDN can comprise multiple levels. Each level's name can only contain letters, digits and hyphens, with each
level separated by a period (dot). A level name cannot start or end with a hyphen, and the final level name must start
with a letter.
level separated by a period (dot). A level name cannot start or end with a hyphen, and the final level name must start
with a letter.
Cluster pre-shared key
The Expressway uses IPsec (Internet Protocol Security) to enable secure communication between each cluster peer.
The Cluster pre-shared key is the common IPsec access key used by each peer to access every other peer in the
cluster.
cluster.
Note
: each peer in the cluster must be configured with the same Cluster pre-shared key.
Setting configuration for the cluster
You should only make configuration changes on the master 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.
change the cluster's configuration.
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Cisco Expressway Administrator Guide