Specifications

Network Configuration Concepts
195
The controller should be located behind a network Layer 2
switch.
“LAN architecture” on page 202
Ensure that the PPS rate of the routers and switches is
adequate for the amount of voice traffic expected.
“WAN layer 3 priority” on page 213
Wherever possible, provide the most bandwidth available.
Use full duplex instead of half duplex.
“Full duplex network basics” on page 218
“Half duplex network basics” on page 219
The 3300 ICP and IP phone Ethernet ports are hard-coded to
auto-negotiate. Ensure that the network Layer 2 ports are also
configured to auto-negotiate.
“IP Phone LAN Speed Restrictions” on
page 289
If the network consists of multivendor units, ensure that they
all inter-operate correctly.
Use MTU on routers, especially for slower-speed links
(anything less than T1 rates).
“Serialization Delay” on page 207
Ensure that end-to-end delay, jitter, and packet loss are within
acceptable bounds.
“General Guidelines for Quality of Service” on
page 199
Ensure that there is sufficient bandwidth on a WAN link for the
amount of expected traffic. Do not overload.
“WAN connections” on page 200
Provide a realistic blocking number for IP trunk restriction
(consider bandwidth).
“IP networking and Use of Compression” on
page 222
Do not share the voice VLAN with data devices.
Place softphones (PC-based), i.e. MiCollab Client Softphone,
on the data VLAN and enable TOS-to-COS conversion
(requires L2/L3 switch).
“TOS-to-COS (IEEE 802.1p) mapping and
softphones” on page 217
Ensure routers support DHCP forwarding, or provide multiple
DHCP servers and copy phone-specific information between
DHCP servers to ensure phones start up correctly.
“Start-Up Sequence and DHCP” on page 230
Ensure routers support ICMP Redirect to reduce bandwidth
requirements when the default gateway device is not the
correct one to direct traffic to.
To get the maximum data rate from a phone, connect a
100BaseT NIC on the PC to the phone and ensure that it is
configured for auto-negotiation. The phone defaults to the
slowest speed for both ports.
“IP Phone LAN Speed Restrictions” on
page 289
Ensure CAT 5 or better cabling is installed to get best
performance. CAT 6 may be required for patch cable if a
number of patch panels are used in a wiring run.
“CAT 3 Wiring Practices” on page 293
Consider the subnet size and the NetBIOS configuration used.
A subnet of 254/24 devices works well.
“NetBIOS and PC Settings” on page 257
Table 62: Network Configuration Guidelines (continued)
Guideline For more information
Page 2 of 3