Detect Subscriber Access Failures

Instruction to alert the network administrator when subscribers are denied access to bandwidth services because there is no more available bandwidth

Providers of bandwidth services (ISPs, universities, hosted buildings, and so on) typically allocate bandwidth equitably, based on contracted amounts rather than the needs of particular applications. For example, a university might provision 256 Kbps for each dormitory room. A landlord of a wired office building might do the same for each office.

The PacketWise feature to implement equitable bandwidth is called a dynamic partition. For instructions to implement a solution using dynamic partitions, see Provision Bandwidth Equitably.

The focus of this recommendation is to automatically be informed when you run out of bandwidth for subscribers. It assumes you have implemented a solution as described in Provision Bandwidth Equitably, and that you chose any of the options that limits the number of concurrent subscribers.

It is possible that more subscribers try to access service than is permitted in your settings for your dynamic partition and its parent traffic class. In this case, inactive subscribers' dynamic partitions are retired to make room for new requests. If there are no inactive individual dynamic partitions, then the new user may be denied access because of insufficient bandwidth.

When a subscriber is denied access, PacketWise increments a measurement variable called dynamic-no-partition-count. The adaptive response feature can monitor this measurement variable for the value of interest to you and then take action when fulfilled.

For background on the adaptive response feature, including the definitions for agents, action files, red/yellow/green status categories, and more, see Adaptive Response Overview.

Steps:

Follow the steps in the recommendation called Monitor and Respond to My Own Custom Condition. Use the following values for the steps it describes in each of its three phases:

1. Phase One: Plan your Adaptive Response Agent
   
   You want to define an agent to monitor a partition measurement variable called dynamic-no-partition-count. Checking each two minutes (your interval), you want to send email (your red action) to yourself or the network administrator when at least two subscribers (your red threshold) are denied access. Everything is fine when no subscribers are denied access (your green threshold).
   
   
2. Phase Two: Create your Action Files
   
   • Set up email notification by configuring an SMTP server and defining email recipients.
   • Create the red action file with name RedDeny and script contents that look like:
     #Title: Monitor bandwidth-service denials. Send email if 2 or over
     send email <YourEmailAddress> "Service Access Denied Alert" "A total of $me-value subscribers were denied access on $class-id."
   • Skip defining a green action file.
     
     
3. Phase Three: Add Your Agent
   
   Add your agent with field values as follows:
   
   
   • Select Partition ME Variables for the agent template.
   • Enter Monitor Service Denials for the agent's name.
   • Change the Scoring Interval to 2 minutes.
   • Enter RedDeny.cmd for the red action file's name.
   • Click OK and edit parms.The Edit Agent Entry window opens.

   
   Edit your agent with field values as follows:

   • Change RedThreshold to 2 (the number of subscribers denied access that causes alarm).
   • Change GreenThreshold to 0 (the number of subscribers denied access that causes no alarm).
   • Change ClassName to the name of the parent traffic class with the dynamic subpartitions (/Inbound/renters, for example)
   • Change MeVariableName to dynamic-no-partition-count.
   • Change MeDuration to 2 minutes.
     Save your new agent's definition.
     
     
4. Check your agent's status occasionally and check its reports.