CUBE: mode border-element

[helloguys]

I was trying to understand what exactly does the "mode border-element" do (under "voice service voip").

Yes, the short answer is "to enable CUBE".  But what *exactly* does it do?  For example, without "mode border-element", would there be any commands not available?

IMHO, a voice router is a voice router.  It has dial peers.  It can route calls while doing all kinds of manipulations.  I can do those with a Cisco 28xx router running IOS 12.x, without the "mode border-element" command.  So what am I missing without the "mode border-element"?  Thank you!

[Roger Kallberg]

Normally a router would route calls between a TDM type of circuit, aka an POTS call leg and a VoIP call leg. With CUBE functionality it can route calls between two VoIP call legs.

[helloguys]

Thank you for your info.  A voice router may use SIP trunk, not necessarily TDM trunk.  Also you may use voip dial-peers on a voice router without using the "mode border-element" command.  So what exactly does that command do?

[Roger Kallberg]

A voice router cannot use a SIP trunk as the circuit for PSTN services and route calls to a VoIP service, like a SIP trunk to CM, without CUBE functionality. You’re absolutely correct that you can use voip dial peers on a router without the command, however you can not route calls between two voip call legs. That’s what the command enables with the CUBE functionality.

[M02@rt37]

Hello @helloguys,

Enabling "mode border-element" under "voice service voip" on a Cisco router configures it to operate as a Cisco Unified Border Element "CUBE". CUBE is a feature that provides border element functionality for voice and video networks, specifically designed for SIP-based VoIP networks.

By using "mode border-element," the router gains the ability to perform more advanced functions, such as NAT traversal, protocol normalization, SIP header manipulation, and call admission control. It's not just about basic call routing; it's about handling the complexities of VoIP traffic at the network border.

Without "mode border-element," your router can still handle basic call routing and manipulation tasks using dial peers and other features. However, you would be missing out on the advanced capabilities that CUBE provides for managing VoIP traffic at the network edge.

[helloguys]

Thank you for your reply.  Is there a document to show us what feature is available with CUBE but not possible with regular dial-peers/translation-rules/sip-profiles?  Thank you again!

[M02@rt37]

Hello @helloguys,

https://www.cisco.com/c/en/us/products/collateral/unified-communications/unified-border-element/data-sheet-c78-729692.html

https://www.cisco.com/c/en/us/products/collateral/unified-communications/unified-border-element/white_paper_c11-613550.html

https://www.cisco.com/c/en/us/support/unified-communications/unified-border-element/products-installation-and-configuration-guides-list.html

[helloguys]

Not exactly what I was looking for.  But thank you anyway.

Those datasheets and whitepapers tell us what a CUBE can do.  But didn't say which ones are exclusive to CUBE, which ones can also be done by a regular voice router.  What I was looking for was like - "In such a use case, you need to use CUBE.  Because this can only be done via XYZ.  And XYZ is not available in regular voice routers.  It is only available on CUBE".  Thanks!