n
Use FQDNs (Fully Qualified Domain Names) instead of IP addresses when specifying external addresses
(for example for LDAP and NTP servers, neighbor zones and peers).
n
Use features such as
URI dialing
or
ENUM dialing
.
Default DNS servers
You can specify up to 5 default DNS servers.
n
The VCS only queries one server at a time; if that server is not available the VCS will try another server
from the list.
n
The order that the servers are specified is not significant; the VCS attempts to favor servers that were last
known to be available.
Per-domain DNS servers
In addition to the 5 default DNS servers, you can specify 5 additional explicit DNS servers for specified
domains. This can be useful in deployments where specific domain hierarchies need to be routed to their
explicit authorities.
For each additional per-domain DNS server address you can specify up to 2
Domain names
. Any DNS
queries under those domains are forwarded to the specified DNS server instead of the default DNS servers.
You can specify redundant per-domain servers by adding an additional per-domain DNS server address and
associating it with the same
Domain names
. In this scenario, DNS requests for those domains will be sent
in parallel to both DNS servers.
Tip
: you can also use the
DNS lookup
tool (
Maintenance > Tools > Network utilities > DNS lookup
) to
check which domain name server (DNS server) is responding to a request for a particular hostname.
Caching DNS records
To improve performance, DNS lookups may be cached. This cache is flushed automatically whenever the
DNS configuration is changed.
You can also force the cache to be flushed by clicking
Flush DNS cache
.
Configuring Quality of Service settings
The
Quality of Service
(QoS) page (
System > Quality of Service
) is used to configure QoS options for
outbound traffic from the VCS.
This allows the network administrator to tag all signaling and media packets flowing through the VCS with
one specific QoS tag and hence provide the ability to prioritize video traffic over normal data traffic.
Management traffic, for example SNMP messages, is not tagged.
Supported mechanisms
The VCS supports the
DiffServ
(Differentiated Services) mechanism which puts the specified
Tag value
in
the TOS (Type Of Service) field of the IPv4 header or TC (Traffic Class) field of the IPv6 header.
Cisco VCS Administrator Guide (X8.1.1)
Page 33 of 507
Network and system settings
Network settings