Cisco 7925G Deployment Guide

Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G Deployment Guide
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The cell edge should be designed to -67 dBm where there is a 20-30% overlap of adjacent access points at that signal
level.
This ensures that the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G always has adequate signal and
can hold a signal long enough in order to roam seamlessly where signal based triggers are utilized vs. packet loss
triggers.
Also need to ensure that the upstream signal from the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G
meets the access point’s receiver sensitivity for the transmitted data rate. Rule of thumb is to ensure that the received
signal at the access point is -67 dBm or higher.
It is recommended to design the cell size to ensure that the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and
7926G can hold a signal for at least 5 seconds.
Channel Utilization
Channel Utilization levels should be kept under 50%.
If using the 7925G, 7925G-EX, and 7926G phone, this is provided via the QoS Basic Service Set (QBSS), which
equates to around 105.
Noise
Noise levels should not exceed -92 dBm, which allows for a Signal to Noise Ratio (SNR) of 25 dB where a -67 dBm
signal should be maintained.
Also need to ensure that the upstream signal from the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G
can meet the access point’s signal to noise ratio for the transmitted data rate.
Packet Loss / Delay
Per voice guidelines, packet loss should not exceed 1% packet loss; otherwise voice quality can be degraded
significantly.
Jitter should be kept at a minimal (< 100 ms).
Retries
802.11 retransmissions should be less than 20%.
Multipath
Multipath should be kept to a minimal as this can create nulls and reduce signal levels.
Many different tools and applications can be used to evaluate these items in order to certify the deployment.
• Cisco Prime Network Control System (NCS) for Unified Wireless LAN Management
http://www.cisco.com/en/US/prod/collateral/wireless/ps5755/ps11682/ps11686/ps11688/data_sheet_c78-650051.html
• Cisco Wireless Control System (WCS) for Unified Wireless LAN Management
http://www.cisco.com/en/US/prod/collateral/wireless/ps5755/ps6301/ps6305/product_data_sheet0900aecd802570d0.ht
ml
• Cisco Wireless LAN Solution Engine (WLSE) for Cisco Autonomous Wireless LAN Management
http://www.cisco.com/en/US/prod/collateral/netmgtsw/ps6380/ps6563/ps3915/ps6839/product_data_sheet0900aecd804
10b92.html
• Cisco Spectrum Expert
http://www.cisco.com/en/US/prod/collateral/wireless/ps9391/ps9393/product_data_sheet0900aecd807033c3.html
• Cisco Unified Operations Manager

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