[supercat25]

Just a quick question, how does MDS and browsing on the BlackBerry work when you only have to open a Outbound connection using Port 3101.

[BBAdmin]

Bi-directional

[tktlee]

proxy server

[x14]

Originally Posted by supercat25

Just a quick question, how does MDS and browsing on the BlackBerry work when you only have to open a Outbound connection using Port 3101.

This is all about established connection. The rule on the firewall basically states the connection over port 3101 can only be established from the internal network and denies any request to open a connection from the outside.

Once the BES opens the connection to SRP it maintains that connection for bi-directional communications. If a connection is dropped for whatever reason the BES has to start that communication with RIM again.

So data flow is bi-directional but the firewall rule is set for outbound only. Your BES has to establish the initial connection with the SRP which is outbound.

[Mathos]

Sorry to contradict but nothing comes in via the port 3101 in our entreprise. The logs of the DMZ are formal.

I precisely seek by where the e-mails written on the mobile enter our company.

Any idea ?

[CanuckBB]

Random port number making use of the pre-established connection using outbound 3101.

Or magic.

Whichever you want to believe.

[Mathos]

For the first solution it is annoying for the management of the DMZ.

The second solution..., why not ?

[supercat25]

Thanks BBadmin and X14 for the detailed explaination.

[CanuckBB]

Originally Posted by Mathos

For the first solution it is annoying for the management of the DMZ.

The second solution..., why not ?

Bi-directional comms is never accomplished on a single port. The BES issues an outbound request on 3101. Your firewall will NAT that request along with a random port number. From that point, the connection is maintained thru that randomnly assigned port. That is just the nature of NATed connections. You will never see inbound 3101. I would venture to guess that all you see in your logs are a connection initiated on 3101, followed almost immediately by a connection closed.

[Zro]

Just to add my $0.02 worth, I'm going to address the browsing aspect....

When a BB requests a page from the web, the request is sent to the MDS service (yea, i'm omitting the router connection to the SRP server, etc) and the MDS service uses regular port 80 to request the page. MDS then formulates that page into a BB format and sends it back out to the handheld (again, omitting the 3101 connection, etc).

Zro