Network Configuration Specifics
237
POTENTIAL ISSUES WITH USING LLDP-MED IN CISCO ENVIRONMENTS
The Issue:
Erroneous VoIP QoS values have been noted when using LLDP-MED with the following Cisco
IOS software releases:
•
IOS 12.2(37)
•
IOS 12.2(40)
Cisco switches running the above operating systems with LLDP-MED enabled will issue the
phones these LAN Policy values:
•
Valid VLAN ID
•
L2 (802.1p) = 0 (Incorrect value)
•
L3 (DSCP) = 0 (Incorrect value)
Table 69: Priority levels for the Various Sources of L2/L3 QoS Settings
SOURCE OF L2 &
L3 QOS SETTINGS
PRIORITY
LEVEL
NOTES
Manual Entry (Static)
5
Programmed by installer
DHCP
4
The first time a phone receives DHCP information it must contain an IP
address for the RTC and the TFTP server. This is also true for the double
DHCP fetch mechanism.
If the phone fetches DHCP information a second time, this information will
over write the previous values.
DHCP can be used to provide separate L2 and L3 QoS values for both
signalling and media.
If DHCP has only been programmed with one value, the phone will use this
value for both signalling and media.
LLDP-MED
3
Information obtained from L2 switch
CDP
2
CDP does not provide values, however if CDP is detected on the LAN the
phones will use Cisco ‘inferred’ values.
L2 Value = 5, L3 DSCP Value = 46
Default Values
1
L2 Default Value = 6, L3 DSCP Value = 46. See additional
Notes
below.
Notes:
1.
A DSCP value of 46 is recommended for newer installations using DSCP-aware routers. Value
46 will place the voice into the Expedited Forwarding Queue (EF).
2.
Depending on certain network conditions the phone will use different DSCP default values. The
default values under specific conditions are:
•
If the VLAN information was learnt via CDP, signalling will use a DSCP value of ‘46’ and voice
will use a DSCP value of ‘46’.
•
In situations where VLAN information cannot be learnt from either CDP or DHCP, the phone
will use a DSCP value of ‘0’ for both signalling and voice.
Содержание MiVOICE BUSINESS
Страница 1: ...Mitel MiVoice Business RELEASE 7 2 ENGINEERING GUIDELINES ...
Страница 15: ...Chapter 1 ABOUT THIS DOCUMENT ...
Страница 16: ......
Страница 22: ...Engineering Guidelines 8 ...
Страница 23: ...Chapter 2 SYSTEM OVERVIEW ...
Страница 24: ......
Страница 28: ...Engineering Guidelines 14 ...
Страница 29: ...Chapter 3 TYPICAL CONFIGURATIONS ...
Страница 30: ......
Страница 73: ...Chapter 4 PHONES AND VOICE APPLICATIONS ...
Страница 74: ......
Страница 95: ...Phones and Voice Applications 81 Figure 9 ICP Connection Paths and Limitations ...
Страница 100: ...Engineering Guidelines 86 ...
Страница 101: ...Chapter 5 POWER ...
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Страница 128: ...Engineering Guidelines 114 ...
Страница 129: ...Chapter 6 PERFORMANCE ...
Страница 130: ......
Страница 135: ...Chapter 7 APPLICATIONS ...
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Страница 142: ...Engineering Guidelines 128 ...
Страница 143: ...Chapter 8 EMERGENCY SERVICES ...
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Страница 151: ...Chapter 9 IP NETWORKING ...
Страница 152: ......
Страница 167: ...Chapter 10 LICENSING ...
Страница 168: ......
Страница 183: ...Chapter 11 BANDWIDTH CODECS AND COMPRESSION ...
Страница 184: ......
Страница 209: ...Chapter 12 NETWORK CONFIGURATION CONCEPTS ...
Страница 210: ......
Страница 244: ...Engineering Guidelines 230 ...
Страница 245: ...Chapter 13 NETWORK CONFIGURATION SPECIFICS ...
Страница 246: ......
Страница 309: ...Appendix A CAT 3 WIRING ...
Страница 310: ......
Страница 315: ...CAT 3 Wiring 301 Figure 55 CX MX MXe AX and LX Minimum Cable Standard ...
Страница 316: ...Engineering Guidelines 302 ...
Страница 317: ...Appendix B INSTALLATION EXAMPLES ...
Страница 318: ......
Страница 335: ...Appendix C LLDP AND LLDP MED CONFIGURATION EXAMPLES ...
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Страница 347: ...Appendix D VOIP AND VLANS ...
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Страница 353: ...Appendix E VOIP SECURITY ...
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