Bandwidth, Codecs and Compression
183
usable bandwidth is likely to drop when the backup link is activated. Each individual business
must consider if this is likely to cause problems and either set the limits to match, or accept
that, under failure conditions, some call issues may occur.
A load sharing link is similar to the standby link described above, since the overall bandwidth
is again likely to be reduced. Again, the business needs to determine what level of bandwidth
is acceptable.
Mitel recommends that you determine the minimum available bandwidth during the failure
condition, and use this as the normal limit. This will ensure that a failed WAN link has minimal
impact on the voice quality.
Routers that can deal with load sharing and hot standby links include protocols such as Virtual
Router Redundancy Protocol (VRRP) and/or Hot Standby Router Protocol (HSRP).
Example Hot Standby link
Suppose the business has two WAN links:
•
1.544Mbits/s
•
256kbits/s
Normally, the main 1.544 Mbit/s link is active and there is sufficient bandwidth for voice and
data. If this link fails, the backup is reduced to 256 kbit/s. To minimize voice issues during link
failure, the lower link rate should be used to determine available voice bandwidth. Nevertheless,
the business may be willing to handle the occasional outage and reduced voice quality to get
an increased number of voice channels.
Example load sharing link
Suppose the business has two WAN links that provide load sharing:
•
1.544Mbit/s
•
1.544Mbit/s
Together these two links can provide an aggregate bandwidth of around 3 Mbit/s, but during a
failure, this will drop to 1.544Mbit/s. Mitel recommends that the bandwidth allocation for voice
in this case be 1.544Mbit/s, but again, this is dependent on the requirements of the individual
business.
Additional information
For more details and for programming information refer to the Mitel
System Administration Tool
Help
for MiVoice Business.
Inter-zone bandwidth settings
As well as defining the zones and links between locations, the available bandwidth also needs
to be defined. Generally the available bandwidth on these links is also determined by the WAN
link protocol. This could be a dedicated link running cPPP, or may be a more general purpose
connection such as MPLS, or xDSL. Although the payload (IP) is common to these WAN
protocols, the bandwidth on the physical wire link may not be. The MiVoice Business system
considers the throughput, or payload bandwidth, with some minor overhead and is defined in
Table 54.
Summary of Contents for MiVOICE BUSINESS
Page 1: ...Mitel MiVoice Business RELEASE 7 2 ENGINEERING GUIDELINES ...
Page 15: ...Chapter 1 ABOUT THIS DOCUMENT ...
Page 16: ......
Page 22: ...Engineering Guidelines 8 ...
Page 23: ...Chapter 2 SYSTEM OVERVIEW ...
Page 24: ......
Page 28: ...Engineering Guidelines 14 ...
Page 29: ...Chapter 3 TYPICAL CONFIGURATIONS ...
Page 30: ......
Page 73: ...Chapter 4 PHONES AND VOICE APPLICATIONS ...
Page 74: ......
Page 95: ...Phones and Voice Applications 81 Figure 9 ICP Connection Paths and Limitations ...
Page 100: ...Engineering Guidelines 86 ...
Page 101: ...Chapter 5 POWER ...
Page 102: ......
Page 128: ...Engineering Guidelines 114 ...
Page 129: ...Chapter 6 PERFORMANCE ...
Page 130: ......
Page 135: ...Chapter 7 APPLICATIONS ...
Page 136: ......
Page 142: ...Engineering Guidelines 128 ...
Page 143: ...Chapter 8 EMERGENCY SERVICES ...
Page 144: ......
Page 151: ...Chapter 9 IP NETWORKING ...
Page 152: ......
Page 167: ...Chapter 10 LICENSING ...
Page 168: ......
Page 183: ...Chapter 11 BANDWIDTH CODECS AND COMPRESSION ...
Page 184: ......
Page 209: ...Chapter 12 NETWORK CONFIGURATION CONCEPTS ...
Page 210: ......
Page 244: ...Engineering Guidelines 230 ...
Page 245: ...Chapter 13 NETWORK CONFIGURATION SPECIFICS ...
Page 246: ......
Page 309: ...Appendix A CAT 3 WIRING ...
Page 310: ......
Page 315: ...CAT 3 Wiring 301 Figure 55 CX MX MXe AX and LX Minimum Cable Standard ...
Page 316: ...Engineering Guidelines 302 ...
Page 317: ...Appendix B INSTALLATION EXAMPLES ...
Page 318: ......
Page 335: ...Appendix C LLDP AND LLDP MED CONFIGURATION EXAMPLES ...
Page 336: ......
Page 347: ...Appendix D VOIP AND VLANS ...
Page 348: ......
Page 353: ...Appendix E VOIP SECURITY ...
Page 354: ......
Page 381: ... ...