Configuring ATM/DS3 for VBR-nrt

[mpinkston]

I have a Cisco 1841 router with a fractional frame 384k, T1 data circuit that terminates to a Cisco 3640 ATM/DS3 interface. I was informed that the circuit needs to be configured as a VBR-nrt. Any suggestions on configuring a VBR-nrt sub-interface?

[paolo bevilacqua]

Ask your SP about the CIR and burst value to be configured for FR. He is doing the conversion with ATM and he is the one that sets them.

There no implicit support for vbr-nrt on frame-realy, so all you have to do, is optionally configure shaping to CIR if needed.

[paolo bevilacqua]

To add to this, to the ATM router is ininfluent if VBR is rt or nrt, unless you have multiple PVC in which case rt would preempt nrt in on each "cell slot collision" for transmit.

[rajput_p]

Hi, here is the conf of ATM sub int ATM1/0.21

ip add x.x.x.x

pvc

VPI/VCI

VBR-NRT PCR(kbps) SCR(kbps) MBS(cells)

If still having any doubt please revert.