> ## Documentation Index
> Fetch the complete documentation index at: https://altostrat.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# SIP trunk exhaustion: alarm to expanded capacity in one shift

> Concurrent-call counters peak above the contracted limit. Confirm legitimate traffic, expand the trunk capacity with the carrier, push the SBC change, validate, and update billing — without dropping calls.

Mid-morning, a healthcare customer's call-centre starts seeing 503 Service Unavailable on outbound dials. The carrier's SBC concurrent-call counter for that customer is sitting on the contracted ceiling. The carrier needs to confirm the traffic is legitimate, expand the trunk, push the change without disrupting active calls, and update the billing.

## Systems involved

| System                              | Role                                            |
| ----------------------------------- | ----------------------------------------------- |
| Studio terminal                     | SSH to SBC for live concurrent-call counts.     |
| Voipmonitor / Homer                 | Call quality and pattern history.               |
| Carrier portal (Bandwidth / Telnyx) | Contracted CIC count, change request.           |
| Splynx / homegrown billing          | Customer record, contract terms, billing rules. |
| Microsoft Teams `#voice-ops`        | Internal channel.                               |
| Gmail                               | Customer-facing notice and confirmation.        |
| Studio Procedures                   | `Trunk capacity expansion` runbook.             |

## Walkthrough

<Steps>
  <Step title="Confirm exhaustion is the cause">
    Copilot pulls the SBC's concurrent-call counter for the customer and the rejected-call log. Pattern is unambiguous: rejections fired the moment the counter touched the ceiling, repeatedly, across the morning.
  </Step>

  <Step title="Confirm traffic is legitimate">
    Pull the call pattern from Voipmonitor for the morning. Outbound calls to a normal distribution of customer-service destinations, ASR (Answer Seizure Ratio) is normal, no pumping pattern. The customer is just busier than their contract allows.
  </Step>

  <Step title="Notify the customer fast">
    Through Gmail, send the customer a short note: we're seeing capacity exhaustion, your calls are being briefly rejected, here's what we recommend (uplift your CIC), if you approve we can do it within the hour. Phone call also placed to the customer's IT contact.
  </Step>

  <Step title="Customer approves">
    Customer agrees to a 25 percent uplift. The PSA opportunity is created and won; billing rules will reflect the new ceiling from the change date.
  </Step>

  <Step title="Coordinate with carrier">
    Through the Bandwidth connector, request the trunk uplift. The carrier confirms within 15 minutes. New CIC ceiling: 250.
  </Step>

  <Step title="Push the SBC change">
    SSH to the SBC. Stage the customer's trunk's new call-admission control limit. Approval prompt shows the diff. Push. Active calls are unaffected; new calls now succeed up to 250 concurrent.
  </Step>

  <Step title="Validate">
    Copilot watches the rejected-call counter for 30 minutes. Rejections drop to zero. Concurrent-call counter peaks at 217 during the lunch rush — comfortably inside the new ceiling.
  </Step>

  <Step title="Update billing">
    Update the customer's billing record with the new CIC count and the effective date. The next invoice picks up the prorated change automatically.
  </Step>

  <Step title="Confirmation email">
    Gmail confirmation to the customer: change applied, validated, here's the new ceiling, here's the new monthly. Saved memory: "Customer ACME healthcare runs 23 percent above their contracted CIC during open-enrollment season — review every September."
  </Step>
</Steps>

## Where Studio earns its keep

* The exhaustion and the legitimacy check happen in one workspace — the engineer is not guessing whether to expand or to investigate fraud.
* The customer hears about the issue from the carrier before it shows up in their own dashboards, which is the conversation a healthcare call-centre manager wants.
* The carrier change, the SBC change, and the billing update reference the same ticket and the same effective date.
* The seasonal memory means the next September has a proactive uplift conversation in August, not a 503 on day one.

## Related

<CardGroup cols={2}>
  <Card title="Procedures" icon="workflow" href="../../procedures" arrow="true" cta="Save it">
    `Trunk capacity expansion` runbook with tenant code as the argument.
  </Card>

  <Card title="Memories and search" icon="brain" href="../../memories-and-search" arrow="true" cta="Track patterns">
    Save seasonal patterns so the next year is proactive.
  </Card>
</CardGroup>