Problem transfer TFTP through ASA 5505

Question

Hello,
I have a problem with my ASA 5505, I am not able to transfer files bigger than 100ko using TFTP. Below my archiecture:
CME<->ASA5505<->SW3650
Here is what I get when I try to download a file located on the 3650 on my CME:
CME#copy tftp flash
Address or name of remote host [X.X.X.X]?
Source filename [cmterm-7942_7962-sccp.9-3-1SR4-1[1].tar]?
Destination filename [cmterm-7942_7962-sccp.9-3-1SR4-1[1].tar]?
Accessing tftp://X.X.X.X/cmterm-7942_7962-sccp.9-3-1SR4-1[1].tar...
Loading cmterm-7942_7962-sccp.9-3-1SR4-1[1].tar from 10.52.199.126 (via GigabitEthernet0/0): !... [timed out]
Error reading tftp://10.52.199.126/cmterm-7942_7962-sccp.9-3-1SR4-1[1].tar (Connection timed out)
When I look on the ASA monitoring page, I see that a UDP connection is built between the ASA and the SW3650 but 2 minutes later there are "Teardown UDP connection" messages.
Can you please help me? Due to this transfer issue, I am not able to upgrade my IP Phones (the phones only download the first 2 files because there are smaller than 100ko).
Thank you in advance for your help.
Regards.
Thomas.

Answer 1

Default UDP connection time out is 2 minutes through the ASA.
You can modify the timeout values for the specific flow from a particular source to destination . Try changing the default connection timeout of UDP
ASA(config)# access-list CONNS permit udp host CME ip tftp serverip port
ASA(config)# class-map CONNS
ASA(config-cmap)#match access-list CONNS
ASA(config)# policy-map CONNS
ASA(config-pmap)# class CONNS
ASA(config-pmap-c)# set connection timeout idle 00:30:00
ASA(config)# service-policy CONNS {global | interface interface_name}
you can also globally change the timeout value of UDP using:
ASA(config)# timeout udp 00:30:00
Reference: http://www.cisco.com/c/en/us/td/docs/security/asa/asa82/configuration/guide/config/conns_connlimits.html#wp1080774
HTH
"Please rate helpful posts"