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IP/VC 3521 dial-out problem

tim-griffin
Level 1
Level 1

I have an IP/VC 3521 with 4 ISDN BRI's. I can call into the gateway and bond the channels together from a Polycom Viewstation with no trouble, but when I dial-out from the 3521 to the same Polycom unit, it connects on the first channel, begins bonding mode, the gateway then correctly dials the numbers of the other 3 BRI channels (to make a 256k call) and then the gateway drops all calls. Anyone using a 3521 for dial-out?

6 Replies 6

bbaley
Level 3
Level 3

The following troubleshooting doc might help you out:

http://www.cisco.com/univercd/cc/td/doc/product/ipvc/ipvc10/ipvc3520/chap6.htm

rsteed
Level 1
Level 1

Tim, I work with Polycom and have this unit in my Lab and I have not had this problem. Is this a 256k call you are trying to connect or 384k.

Russ

Either one - and actually a 128K bonded call also. Cisco has shipped an RMA replacement and if that doesn't take care of it it may be an incompatibility between the 3521 and the Verizon BRI's. Verizon says that they have programmed the BRI's as a "package M2". The documentation from Cisco says it requires "pakage S or M". I can't find documentation anywhere that gives the spec's for "package M2" The strange part so far is that the BRI's work okay with the Polycom units when directly connected, and worked for the customer's routers after 911 to back up the frame relay service that was lost.

i dont believe this to be an issue with your BRI lines. You mentioned in a previous post that inbound calls work fine - only outbound calls have a problem. If this is true, your BRIs are configured fine and VZ should not be the issue. This could be a config problem or unique h/w - s/w issue. If you have a TAC case open, let me know and I will take a look at your case. You can reach me at schon@cisco.com

Cisco and RadVision have found a "bug" in the 3521 code that has problems when connected to a National ISDN-1 switch type. They are working on it and even said that we are now one of about 4 customers with the same issue. They swore up and down that it was an ISDN switch misconfiguration even after we had Verizon switch to the recommended "S" package (which costs the customer more due to more features).

aglowack
Cisco Employee
Cisco Employee

The problem is most likely the configuration of your service prefix for outbound calls. You can also telnet into the 3521 and pull a trace that should give you more information.