Welcome to the VoIP Blog

Installing Cisco Unified Communications Manager on VMware Fusion can be tricky if you don't know what settings to use.

The image below shows settings that work well with CUCM 7.x.

This example describes how to use a single public IP address in conjunction with a NAT port range on an IOS router. This would be suitable when using a Cisco UC500 or CME based system behind a router. The diagram below demonstrates the example topology used in this scenario.

Cisco 877 IP Information

Public Interface: 20.20.20.20
Private Interface: 192.168.0.1/30

Cisco Uc500 IP Information

Routed Interface: 192.168.0.2/30
Loopback Interface: 10.1.1.1 (SIP services bound to this interface)

As with any router providing internet access outbound access is likely provided with an overload statement such as this example.

access-list 105 permit ip <inside networks> any
route-map NAT_MAP permit 1
match ip address 105
ip nat inside source route-map NAT_MAP interface dialer1 overload

To allow a SIP mapping is very simple as per the statement below.

ip nat inside source static tcp 10.1.1.1 5060 interface dialer1 5060

However, a large range of ports is required for RTP, and IOS based devices do not yet  have a straight port range option for NAT. The solution in this case is to utilise a route-map that matches the required RTP range (some SIP providers allow you to specify this).

ip access-list extended UDP_RTP
permit udp host <SIP HOST> any range 16384 37248
!
route-map SIP_NAT permit 10
match ip address UDP_RTP
!
ip nat inside source static 10.1.1.1 20.20.20.20 route-map SIP_NAT

Inbound and outbound calls via SIP should function correctly.

This is a useful table when you need to work out the TOS decimal value of DSCP.

DSCP TOS
0 0
1 4
2 8
3 12
4 16
5 20
6 24
7 28
8 32
9 36
10 40
11 44
12 48
13 52
14 56
15 60
16 64
17 68
18 72
19 76
20 80
21 84
22 88
23 92
24 96
25 100
26 104
27 108
28 112
29 116
30 120
31 124
32 128
33 132
34 136
35 140
36 144
37 148
38 152
39 156
40 160
41 164
42 168
43 172
44 176
45 180
46 184
47 188
48 192
49 196
50 200
51 204
52 208
53 212
54 216
55 220
56 224
57 228
58 232
59 236
60 240
61 244
62 248
63 252

NTP Configuration

This configuration applies to version 4.3 and earlier.

The publisher should point to a dedicated NTP external time source.

The subscribers should point to the publisher server.

Complete the following steps:

1.  Disable the Windows Time service (W32Time) on the server.

Open the Windows Services snap-in.
Right click the Windows Time service and select properties.
In the Startup Type box, choose Disabled from the drop-down list.
Click OK.

2.  Edit the NTP demon configuration file. (ndpd.conf)

The ntpd.conf file is located in the "C:\WINNT\system32\drivers\etc" folder.
Edit the file so it contains the required NTP server(s).

Sample:
server 10.20.30.10
server 10.20.30.11
driftfile C:\WINNT\system32\drivers\etc\ntp.drift