Cisco 7925G Deployment Guide

Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G Deployment Guide
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When 802.11b clients exist in the wireless network, then an 802.11b rate must be enabled and only an 802.11b rate can be
configured as a mandatory / basic rate.
The recommended data rate configurations are the following:
802.11 Mode
Mandatory (Basic)
Data Rates
Supported (Optional)
Data Rates
Disabled
Data Rates
802.11a
12 Mbps
18-24, <36-54> Mbps
6, 9, <36-54> Mbps
802.11b
11 Mbps
None
1, 2, 5.5 Mbps
802.11b/g
11 Mbps
12-24, <36-54> Mbps
1, 2, 5.5, 6, 9, <36-54> Mbps
For a voice only application, data rates higher than 24 Mbps (36, 48 and 54 Mbps) can optionally be enabled or disabled, but
there is no advantage from a capacity or throughput perspective and enabling these rates could potentially increase the number
of retries for a data frame.
If deploying in an environment where excessive retries may be a concern, then a limited set of the data rates can be used (e.g.
12, 24, 54), where the lowest enabled rate is the mandatory / basic rate.
For rugged environments or deployments requiring maximum range, it is recommended to enable 6 Mbps as a mandatory /
basic rate.
To preserve high capacity and throughput, data rates of 24 Mbps and higher only can be enabled (24-54 Mbps).
Other applications such as video may be able to benefit from having these higher data rates enabled.
Note: Some environments may require that a lower data rate be enabled due to use of legacy clients, environmental factors or
maximum range is required.
Set only the lowest data rate enabled as the single mandatory / basic rate. Multicast packets will be sent at the highest
mandatory / basic data rate enabled.
Note that capacity and throughput are reduced when lower rates are enabled.
If Call Admission Control (TSPEC) is enabled then the Traffic Stream Rate Set (TSRS) feature will also be enabled, which can
allow lower rates to be enabled for legacy devices, while preventing the Cisco Unified Wireless IP Phone 7925G, 7925G-EX,
and 7926G from transmitting at rates below 12 Mbps for 802.11a and 11 Mbps for 802.11b/g as well as not above 24 Mbps if
the Restricted Data Rates feature in Cisco Unified Communications Manager is enabled. Disallowing packets to be transmitted
at lower rates preserves capacity. Sending voice frames at a more reliable rate (i.e. 24 Mbps) initially can potentially reduce the
number of retries of a frame to ensure the packet transmission is successful on the first try.
See the Product Specific Configuration Options section for information on how to configure the Restrict Data Rates options on
the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G in order to utilize the TSRS feature.
Call Capacity
Design the network to accommodate the desired call capacity.
The Cisco Access Point can support up to 27 bi-directional voice streams for both 802.11a and 802.11g at a data rate of 24
Mbps or higher. To achieve this capacity, there must be minimal wireless LAN background traffic and radio frequency (RF)
utilization.
The number of calls may vary depending on the data rate, initial channel utilization, and the environment.
Max # of Streams
802.11 Mode
Data Rate
13
802.11a or 802.11g + Bluetooth Disabled
6 Mbps

Cisco 7925G Specifications

General

Keypad number of keys	12
Display diagonal	2 \
Display resolution	176 x 220 pixels
Call waiting	Yes
Lines quantity	6 lines
Voice codecs	G.711a, G.722, G.729a, iLBC
Security algorithms	128-bit WEP, SSL/TLS, WPA
Supported network protocols	DHCP, TFTP, DNS, SCCP, SRST
Input voltage	100 - 240 V
Dimensions (WxDxH)	52 x 20 x 127 mm
Minimum system requirements	Cisco Unified Communications Manager 4.1, 4.2, 4.3, 5.1, 6.0, 6.1, 7.0 + Cisco Unified Communications Manager Express 4.3 +
Input frequency	50/60 Hz
Storage temperature (T-T)	-30 - 60 °C
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Product type	IP Phone
Product color	Gray
Safety	UL 60950, CSA 22.2 No.60950, EN 60950, IEC 60950, AS/NZS 60950, IEC 60529 (IP 54)
Certification	47 CFR 15 B ICES-003 B EN 55022 B AS/NZS CISPR 22 B CISPR 22 B VCCI B EN 61000-3-2 EN 61000-3-3 KN 22 EN 55024 EN 50082-1 EN 61000-6-1 EN 300386 EN 60601-1-2 KN
Compliance industry standards	IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.1X, IEEE 802.11e

Weight and Dimensions

Weight	138 g