This document explains this IP phone error message and the necessary
steps to troubleshoot it:
Not Enough Bandwidth
Cisco recommends that you have knowledge of Cisco Communications
Manager (CallMananger) and Cisco IP Phones.
The information in this document is based on Cisco Unified
Communications Manager version 4.x.
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
The Not Enough Bandwidth error message
appears on an IP phone when remote branch offices are called from the Central
When the Cisco CallManager gateway location parameter is set to None,
it is not assigned a location, and there are no restrictions on bandwidth usage
or consumption. A large number of calls through the gateway and back to the
Cisco CallManager central site can potentially exhaust the available bandwidth
between the sites, which causes the Not Enough
Bandwidth error message to appear.
In order to resolve this issue, use the low bandwidth codec between the
sites. In order to use the low bandwidth codec between the sites, configure
locations and regions for both IP phones and their site gateway. Configured
locations (bandwidth) or regions (codecs) for IP phones cannot be guaranteed to
serve their purpose unless gateways are also assigned to locations.
Refer to the
and Regions section of
Locations for more information.
This issue is important to connections that use compression in order to
preserve bandwidth in lower bit rate codecs, such as G.729 and G.723. IP phones
and gateways must also be assigned a region
This issue can be more common for initial configurations or networks
that have increased the site-to-site bandwidth usage
In installations where the locations and regions are already in place,
this error can appear for these reasons:
The number of allowed calls between sites is exceeded. In other
words, all the allowed bandwidth is consumed. Each time a call is initiated
between locations, Cisco CallManager deallocates a certain amount of bandwidth
from the configured pool based upon the codec used for the call. When there is
not enough bandwidth in the pool for a given call, the Not Enough Bandwidth
message appears on the phone that tries to make the call.
In some of the initial versions of Cisco Communications Mananger
(Cisco CallManager), this error sometimes occurs even when the limit is not
reached. This is due to bugs in the Cisco Communications Mananger where the
bandwidth is not returned to the pool by the disconnected calls. These problems
are fixed in the latest service packs. In order to resolve the issue, upgrade
to the latest service packs.
This error message might appear when an incorrect server name is used
in the CCM server group configuration. Ensure that the correct server name is
added under the CCM server group configuration.
If possible, try to restart the Database Layer (DBL) Monitor Service.
Restart Cisco CallManager for an immediate workaround to this
In order to monitor bandwidth, complete these steps:
Create a LocationsTraceDetailsFlag service parameter in Cisco
CallManager service parameters. Make the type boolean, and set the value to
Enable detailed traces for the Cisco CallManager service. Specify the
calling and called number, as well as when the problem occurs.
Check the amount of bandwidth available in all locations with
Perfmon. Add the counters CurrentAvailableBandwidth and MaxAvailableBandwidth
from the Cisco Locations object. This puts bandwidth values in the trace file
for each call. Look at the trace file in order to determine if it runs out of
bandwidth and when.