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Voice Traffic through VPN

Hi Experts,

I need to create a VPN to permit only Voice traffic. So i should mention the protocols in the Access rule for VPN, right?

Which portnumbers/protocol should i mention in ACL for permitting only Voice traffic.



Thanks and Regards, Vipin
Cisco Employee

Voice Traffic through VPN

when you say only voice traffic i assume its only ip phones and call manager traffic you can specify this as your vpn acl

the reason i am saying open all ports is because they use random ports

in any case no harm in allowing all the traffic between phones and call managers, do you have any particular concern which you are looking to address


Voice Traffic through VPN

Hi all,

I am having this same problem. I have the VPN successfully setup between both sites, and the phones at the branch office are able to connect to the HO. However, the phones only register but no tone comes to the phones, neither do they ring out when they are called. The IP phones are Avaya boxes and the call manager is also an Avaya system. I however have an 1800 router and 871 router at the HO and branch office respectively.

I have a 1MB radio link at the HO and 256k at the branch office. The VPN is setup purely for the phones and nothing more.

I suspect the bandwidth of the tunnel may be the problem because when i run a show interface tunnel command, below is what i get:

ROUTER#sh int tun0

Tunnel0 is up, line protocol is up

  Hardware is Tunnel

  Description: Tunnel to HO

  Internet address is

  MTU 1514 bytes, BW 9 Kbit/sec, DLY 500000 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation TUNNEL, loopback not set

  Keepalive not set

  Tunnel source, destination

  Tunnel protocol/transport IP/IP

  Tunnel TTL 255

  Fast tunneling enabled

  Tunnel transmit bandwidth 8000 (kbps)

  Tunnel receive bandwidth 8000 (kbps)

  Last input 00:45:29, output 00:45:31, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 1220

  Queueing strategy: fifo

  Output queue: 0/0 (size/max)

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 0 bits/sec, 0 packets/sec

     1719 packets input, 227853 bytes, 0 no buffer

     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

     3116 packets output, 479098 bytes, 0 underruns

     0 output errors, 0 collisions, 0 interface resets

     0 output buffer failures, 0 output buffers swapped out


Any ideas?