Hi All,

I've got a client who's got one remote site that's using an Adtran 612

router using NAT. This is one that's not listed at all on the either
good or known bad list that Craig maintains.

His other sites are using routers on the list, and they seem to be
just fine. However, this one just doesn't seem to want to connect.
about 30 seconds of trying, the VPN client times out (we are just
trying to
use the VPN client for IP connectivity into their network at this
time, not
even trying a NW login). As I said, the problem doesn't seem to be
with the
BorderManager 3.7 server, since other sites using listed (good)
routers w/
NAT have no problem getting in.

I took packet traces from a good connection and the problem
connection, and
noticed that they both begin the same. There seems to be 2 datagramsexchanged setting up the tcp connection, then an exchange of 8
between the nodes, then the BM server sends a FIN ACK to the client.
There's another exchange of 2 datagrams, then the client sends the BM
a FIN ACK. In all these cases, the client's tcp port is dynamic, and
the BM
server's tcp port is 353.

Next, the client sends the BM server 2 udp datagrams, both of which
have 353
as the source and dest ports.

Next, the server sends 2 IP port 57 datagrams to the client.

Next the client sends a FIN ACK to back to the BM server.

Then the BM server sends another IP port 57 datagram to the client.

At this point, the packet traces diverge. The "good" trace goes right
IP port 57 data transfers back and forth between the BM server and the


However, the "bad" trace gives me "Window Frozen" errors (using
It also appears that this datagram is a retransmission of the last FIN
from the client to the BM server (same seq# and ack#) The next
datagram is
a port 57 from the BM server to the client.

Next, the client sends the server another udp 353 datagram to 353 on
the BM
server, followed by the server sending the client a port 57 datagram.
continues over and over again, until the client times out. There's
another occasional repeat of the "Window Frozen" error that I
before, again I believe that these are retransmissions.

I've contacted Adtran for help, but so far, I haven't heard anything

So there is some TCP comunications going on, and a TCP connection is
but it seems that there's a problem with stabilizing the VPN

Any help would be very much appreciated.