GPRS / Data Services

Dual Mode (GSM/3G & CDMA) Blackberry

Blackberry (BB) released dual mode handset. This handset can be used in GSM/3G or in CDMA network.

Based on my experience, even tough BB has been attached to GSM/3G Network, it seems BB still trying to use CDMA APN at the first time. If the APN rejected (due to operator’s APN differences), then BB will try to PDP using the GSM/3G APN.

This behavior will make a little problem if provider trying to implement APN Redirection

The aim of applying APN redirection for BB subscriber is to handle wrong APN requested by subscriber.

In the simple way, SGSN will redirect all non providers APN requested by subsciber to blackberry.net if and only if the subscriber is a blackberry subscriber

So, if the subscriber uses other APN eg emgsm.vzw3g.com, celcom, vodafone, etc, SGSN will redirect the APN to blackberry.net as long as they’re blackberry subsciber.

Technically, the APN parameter value on Active PDP Context Request Is emgsm.vzw3g.com, but the APN parameter value on PDP Context Creation send by SGSN to GGSN is blackberry.net.

Since the subscriber eligible to use APN blackberry.net (subscribed in HLR), then GGSN will allow this subsciber and give PDP IP to the subsciber

The BB device will only send packet to the RIM IP.

Because BB handset “feel” that the PDP Activation was successful using CDMA APN then BB will send the payload traffic to RIM CDMA IP instead of RIM GSM IP.

RIM will reject the packet because RIM only open the packet for GSM IP. This is what I called problem.

Advertisements

Discussion

No comments yet.

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Archives

Twitter Updates

Error: Please make sure the Twitter account is public.

%d bloggers like this: