[c-nsp] Issues with 2921, NAT and Skype?

[Scott Granados]

Hi,

I have a strange problem and I’m not familiar with the inner workings of Skype to know for sure but I believe I have a problem caused by my NAT config.  In some instances, after 1 minute the video will freeze especially when using a Skype gateway to another service.  Point to point Skype calls for the most part work and audio is generally unimpacted.  I have a very basic NAT setup which follows.

interface GigabitEthernet0/1
 bandwidth 50000
 ip address 1.2.3.1 255.255.255.252
 ip access-group 101 in
 ip nat outside
 ip virtual-reassembly in
 media-type sfp
!
interface GigabitEthernet4/0
 ip address 4.3.2.1 255.255.255.252
 ip access-group 102 in
 ip nat inside
 ip virtual-reassembly in
!
ip nat inside source list 120 interface GigabitEthernet4/0 overload

Is there a modification to this that might better supports the needs of Skype callers originating requests from behind this router?  Any pointers that might have some general best practices for this type of setup?  Any ideas would be most appreciated.

Thank you
Scott