Oversubscripted Bandwidth Points on 7206VXR

Question

Hi,
I just want to ask about bandwidth points on cisco 7206VXR with NPE-G1.
What will happen if bandwidth points oversubscripted on one of the PCI bus?
This is the sample:
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PCI bus mb1 (Slots 1, 3 and 5) has a capacity of 600 bandwidth points.
Current configuration on bus mb1 has a total of 0 bandwidth points.
This configuration is within the PCI bus capacity and is supported.
PCI bus mb2 (Slots 2, 4 and 6) has a capacity of 600 bandwidth points.
Current configuration on bus mb2 has a total of 640 bandwidth points.
The set of PA-2FE, PA-POS-2OC3, and I/O-2FE qualify for "half bandwidth points" consideration, when full bandwidth point counting results in oversubscription, under the condition that only one of the two ports is used. With this adjustment, current configuration on bus mb2 has a total of 340 bandwidth points.
This configuration is within the PCI bus capacity and is supported under the above condition.
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What happen when 2 ports of PA-POS-2OC3 activated?
Thx
Iwan

Answer 1

72xx PAs are hot-swappable. What we've done in similar situations is to schedule a maintenance window, copy the configuration to a text editor and search/replace the affected interface numbers, add a "no shutdown" on the config to the physical interface to which the card is going.
Console in. At the scheduled hour yank, shove, paste the config. Your customers on the affected card should be back up in less than two minutes.
Not really relevant to this specific issue but it is generally a good idea to have a specific maintenance window at specified off hours for singly-homed customers (and even multiply-homed just in case). 2:00 AM Sunday morning local time as an example. Situations like the above, upgrading IOS for security fixes or features, etc. will always come up from time to time. If it's expected it usually isn't a big deal and they often appreciate the attention to keeping your network up to date.
Back to your original question, things will still work in an oversubscribed state unless you're pushing near full wire speed in which case you'll start to get packet loss. If you need to open a TAC case or get support you'll be told not to do it, and perhaps to fix the issue before getting further support.
This document:
http://www.cisco.com/en/US/products/hw/routers/ps341/products_tech_note09186a00800c814a.shtml
says "You can use a 7200 series router with a PA configuration that exceeds the guidelines that the Cisco 7200 Series Port Adapter Installation Requirements provide. However, in order to prevent the occurrence of anomalies while the router is in use, restrict the type of PA that is installed in the router in accordance with the guidelines. Additionally, in order to have Cisco Technical Support troubleshoot these anomalies, your PA configuration must be within the guidelines."
which may give you the ammunition you need.