Polycom H340 - Manual (Page 28)

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Deploying SpectraLink e340, h340 and i640 Wireless Telephones BEST PRACTICES GUIDE
October 2010
Figure 9 - Measuring Network Jitter
In a multiple SVP Server configuration, jitter is measured from the SVP Server that is responsible for the traffic
through a given AP to a wireless telephone. This may be different than the SVP Server that is acting as a proxy for
the wireless telephone to the IP PBX. Refer to Section 4.1.3 for additional multiple SVP Server information.
SpectraLink handsets have a diagnostic option that includes jitter measurement. The calculated jitter shown in this
mode is not the jitter described above because it includes delays in the AP, radio link and queue times inside the
wireless telephone. Jitter information from the handset diagnostic mode should only be used as a guideline for
diagnosing major network or radio link problems.
6.4 DHCP Requirements
The SpectraLink Wireless Telephone is configured by default to utilize DHCP in order to obtain an IP address and
the necessary DHCP options to allow the phone to operate normally. For the different IP protocols available with the
SpectraLink handset there are a number of different DHCP options that would be used. However, there are also a
number of DHCP options that are universal required regardless of the IP protocol implementation. Additionally, the
DHCP options required for a Telephony Gateway implementation vary somewhat from the IP protocol deployments.
Operationally, the handset functions the same regardless of the implementation when using DHCP. This means all
that is changing is the DHCP options the handset will require in order to function properly. For Telephony Gateway
deployments the handset will acquire its IP address from the DHCP server Scope Address Pool and its Subnet mask
in addition to the most basic options from the DHCP server Scope Options. The expectation when deploying a
Telephony Gateway system is that the handset will reside on the same IP subnet as the Gateway in order to
generate the necessary multicast frames that will allow it to locate and register with the Telephony Gateway. Once
the handset registers, the remaining options that would normally be handled via DHCP, such as TFTP, are provided
by the Telephony Gateway.
When the license option in the wireless phone is set for one of the IP protocols the handset will require several other
DHCP options in order to function properly. In addition to the base DHCP options required by the Telephony