Defining Priority Level For Vns Traffic; Setting Up A Vns For Voice Traffic - Siemens HiPath C10 User Manual

hwc_vnsconfiguration.fm
Virtual Network configuration

Defining priority level for VNS traffic

5. Click the Filtering tab.
6. Define a default filter that will control specific network access for any wireless device users
on this VNS. For more information, see Section 7.6, "Configuring filtering rules for a VNS",
on page 153.
These rules should be very restrictive and the final rule should be a Deny All rule. The
non-authenticated filter for a VNS with no authentication will not have a Captive Portal page
for login.
7. To save your changes, click Save.
7.10 Defining priority level for VNS traffic
Voice over Internet Protocol (VoIP) using 802.11 wireless local area networks are enabling the
integration of internet telephony technology on wireless networks. Various issues including
quality-of-service (QoS), call control, network capacity, and network architecture are factors in
VoIP over 802.11 WLANs.
Wireless voice data requires a constant transmission rate and must be delivered within a time
limit. This type of data is called isochronous data. This requirement for isochronous data is in
contradiction to the concepts in the 802.11 standard that allow for data packets to wait their
turn, in order to avoid data collisions. Regular traffic on a wireless network is an asynchronous
process in which data streams are broken up by random intervals.
To reconcile the needs of isochronous data, mechanisms are added to the network that give
voice data traffic or another traffic type priority over all other traffic, and allow for continuous
transmission of data.
In order to provide better network traffic flow, the Controller, Access Points and Convergence
Software provides advanced Quality of Service (QoS) management. These management
techniques include:
WMM (Wi-Fi Multimedia) – Enabled globally on the Wireless AP, the standard provides
●
multimedia enhancements that improve the user experience for audio, video, and voice
applications. WMM is part of the 802.11e standard for QoS.
IP ToS (Type of Service) or DSCP (Diffserv Codepoint) – The ToS/DSCP field in the IP
●
header of a frame is used to indicate the priority and Quality of Service for each frame. The
IP TOS and/or DSCP is maintained within CTP (CAPWAP Tunneling Protocol) by copying
the user IP QoS information to the CTP header—this is referred to as Adaptive QoS.
7.10.1

Setting up a VNS for voice traffic

In order to set up a VNS for voice-over-IP traffic, a number of factors should be considered on
the enterprise network and in the Controller, Access Points and Convergence Software system.
On the enterprise network, the wireless telephone users will require access to:
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HiPath Wireless Controller, Access Points and Convergence Software V4.0, C10/C100/C1000 User Guide
A31003-W1040-U101-1-7619, July 2006 DRAFT