Oct <var data-var='date'> 1</var>, <var data-var='time'>04:30</var> MDT Completed - The scheduled maintenance has been completed. Oct <var data-var='date'> 1</var>, <var data-var='time'>00:30</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Sep <var data-var='date'>29</var>, <var data-var='time'>15:21</var> MDT Scheduled - Purpose: Patching and preventative maintenance. Systems Affected: Microsoft: -Microsoft Teams - Migrate MAPS circuits in Ashburn to new cross-connects and test failover afterward ***Possible Impact: There is no expected impact during the circuit migration. During the failover testing, we will intentionally shutdown primary paths to force traffic over the backup connections and test failover performance. This failover testing could result in a very brief loss of audio or dropped calls.

Out-Of-Cycle Maintenance

Sep <var data-var='date'>20</var>, <var data-var='time'>04:00</var> MDT Completed - The scheduled maintenance has been completed. Sep <var data-var='date'>19</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Sep <var data-var='date'>11</var>, <var data-var='time'>09:32</var> MDT Scheduled - Purpose: Patching and preventative maintenance on multiple systems. Systems Affected: Cisco: -Webex - Domestic US Webex Connectivity Optimization ***Possible Impact: Cisco Webex services may experience a brief interruption while improvements are made to strengthen connectivity and increase service resiliency between Cisco and CallTower.

Scheduled Maintenance

Sep <var data-var='date'>19</var>, <var data-var='time'>04:00</var> MDT Completed - The scheduled maintenance has been completed. Sep <var data-var='date'>18</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Sep <var data-var='date'>11</var>, <var data-var='time'>09:31</var> MDT Scheduled - Purpose: Patching and preventative maintenance on multiple systems. Systems Affected: Cisco: -Webex - APAC Webex Connectivity Optimization ***Possible Impact: Cisco Webex services may experience a brief interruption while improvements are made to strengthen connectivity and increase service resiliency between Cisco and CallTower. -Cisco Jabber / MRA Phones - Security Update Expressway Clusters for CUCM ***Possible Impact: CallTower will be upgrading the Edge servers for Jabber and MRA Edge Phone Device. Users will experience a connectivity loss with their Jabber Client/Services and/or MRA Edge connection Phones. Voice: - Hong Kong Masergy Circuit Migration ***Possible Impact: Legacy OneStream voice services hosted in Hong Kong may experience a temporary interruption. Active calls may be disconnected, and new call setup may be unavailable while connectivity services are relocated within the datacenter. Failover and redundant service configurations will minimize downtime. Service will be restored upon completion of the maintenance activities. - London Infrastructure Maintenance ***Possible Impact: During this maintenance window, services hosted in the Telehouse London datacenter may experience a brief interruption as network infrastructure is upgraded. Any service impact is expected to be limited to the duration of the maintenance activity, and services will be restored immediately upon completion.

Sep <var data-var='date'>18</var>, <var data-var='time'>04:00</var> MDT Completed - The scheduled maintenance has been completed. Sep <var data-var='date'>18</var>, <var data-var='time'>00:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Sep <var data-var='date'>16</var>, <var data-var='time'>16:22</var> MDT Scheduled - Purpose: Patching and preventative maintenance. Systems Affected: Microsoft: -Microsoft Teams - Migrate MAPS circuits in Ashburn to new cross-connects and test failover afterward ***Possible Impact: There is no expected impact during the circuit migration. During the failover testing, we will intentionally shutdown primary paths to force traffic over the backup connections and test failover performance. This failover testing could result in a very brief loss of audio or dropped calls.

Sep <var data-var='date'>17</var>, <var data-var='time'>13:02</var> MDT Resolved - CallTower has continued to monitor the issue following this morning's patch and has confirmed customers are successfully provisioning Direct Routing (DR) users in CallTower Connect for GCC High customers. This issue is now considered resolved. CallTower will be closing this master case and all associated cases. Within three business days, an Official Root Cause Analysis (RCA) or a Preliminary RCA will be available and provided to customers upon request. Sep <var data-var='date'>17</var>, <var data-var='time'>09:12</var> MDT Monitoring - CallTower deployed a corrective patch early this morning to resolve the issue affecting Direct Routing (DR) user provisioning in CallTower Connect for GCC High tenants. CallTower is currently monitoring the environment to confirm the issue has been fully resolved. CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. This issue is being investigated as a top priority. Sep <var data-var='date'>16</var>, <var data-var='time'>16:58</var> MDT Identified - CallTower engineers have identified the root cause of the issue affecting Direct Routing (DR) user provisioning in CallTower Connect for GCC High customers. A corrective patch will be implemented after business hours this evening. For customers requiring immediate assistance, CallTower Support has a temporary workaround available. Please reach out to support@calltower.com for assistance. CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. This issue is being investigated as a top priority. Sep <var data-var='date'>16</var>, <var data-var='time'>16:13</var> MDT Investigating - CallTower is currently investigating an issue affecting the provisioning of Direct Routing users in CallTower Connect for GCC High tenants. Customers may experience errors when assigning DIDs or validating Voice Apps in GCC High environments. CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. This issue is being investigated as a top priority.

Teams Direct Routing (GCC High) — DID Assignment and Voice App Provisioning Errors

Sep <var data-var='date'> 4</var>, <var data-var='time'>10:40</var> MDT Completed - The scheduled maintenance has been completed. Sep <var data-var='date'> 3</var>, <var data-var='time'>15:22</var> MDT Scheduled - CallTower will be conducting emergency maintenance affecting Cisco Webex services. Purpose: Cisco Webex infrastructure to improve service stability and reliability. Impact: Service impact is expected to be minimal. During the implementation of changes, any active Cisco Webex calls may be disconnected. Redundant routing has been put in place to minimize further impact throughout the maintenance window. Systems Affected: Cisco Webex Calling Services Outage: No

OUT OF CYCLE MAINTENANCE

Aug <var data-var='date'>31</var>, <var data-var='time'>20:30</var> MDT Completed - The scheduled maintenance has been completed. Aug <var data-var='date'>31</var>, <var data-var='time'>20:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Aug <var data-var='date'>14</var>, <var data-var='time'>09:33</var> MDT Scheduled - MasterFax - Sunset End-of-Service ATAs (SN prefix: D) Purpose: Sunset MP202B devices as prerequisite of future security update. Systems Affected: CT Cloud Fax (MasterFax) Impact: Legacy MP202B ATAs will no longer be able to connect to our MasterFax servers after the maintenance window. If your ATA's serial number starts with "D" and you have not arranged temporary continued access through our Client Success team, please contact accountmanagement@calltower.com. Outage: No

Aug <var data-var='date'>23</var>, <var data-var='time'>22:30</var> MDT Completed - The scheduled maintenance has been completed. Aug <var data-var='date'>23</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Aug <var data-var='date'>14</var>, <var data-var='time'>09:38</var> MDT Scheduled - NOAM CT Cloud Voice - Test CommPortal and SIP PS failover Purpose: Test failover between CT2CHIWAF01 and CT2DALWAF01 Systems Affected: CT Cloud Voice Impact: Users may need to log back into CommPortal and/or CT Cloud Communicator Outage: Yes

Aug <var data-var='date'>22</var>, <var data-var='time'>04:00</var> MDT Completed - The scheduled maintenance has been completed. Aug <var data-var='date'>21</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Aug <var data-var='date'>14</var>, <var data-var='time'>09:36</var> MDT Scheduled - Reboot Call Manager Environment Purpose: Reboot all clusters and nodes inside clusters Systems Affected: Cisco Call Manager: Impact: Server Reboots of the Cisco Unified Communications Manager will occur. Your phone will re-register to the next server in the Server list. Calls in progress 'should' remain up until the call has ended. Phone will most likely re register multiple times during the MW time. This is expected behavior Outage: No NOAM CT Cloud August 2026 maintenance Purpose: Transfer CFS and EAS service for NOAM Meta from CHI to DAL Systems Affected: CT Cloud SIP and Voice Impact: New calls attempted during service transfer may fail to setup, calls in progress will not be affected. Any failed calls should be re-tried. Downtime will be 5 minutes or less while services are transferred to redundant servers for monthly maintenance. Impact: Jabber Clients will receive a Certificate Warning. Please be aware that this is expected behavior and all users will need to accept this before signing back in. Outage: Yes

Aug <var data-var='date'>16</var>, <var data-var='time'>23:00</var> MDT Completed - The scheduled maintenance has been completed. Aug <var data-var='date'>16</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Aug <var data-var='date'>14</var>, <var data-var='time'>09:28</var> MDT Scheduled - CT Cloud Voice - Renew legacy SSL certs Purpose: Renew legacy certs: - userchat.appiaservices.com (SMS for CT Cloud Voice) - userportal.appiaservices.com (Legacy CommPortal) Systems Affected: CT Cloud Voice users with SMS Impact: - Users may need to log back into CT Cloud Communicator. Downtime will be 5 minutes or less while the new certificate is loaded. Outage: Yes We apologize for the short notice.

Jul <var data-var='date'>21</var>, <var data-var='time'>12:00</var> MDT Completed - The scheduled maintenance has been completed. Jul <var data-var='date'>21</var>, <var data-var='time'>11:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Jul <var data-var='date'>20</var>, <var data-var='time'>12:34</var> MDT Scheduled - Purpose: Patching and preventative maintenance on multiple systems. Systems Affected: CT Text: -CT Text Down Vendor Emergency Maintenance ***Possible Impact: The CT Text SMS service will be down due to emergency maintenance by the downstream vendor. This service could potentially be down for 1 hour and return to normal at 12:00 PM MDT. We apologize for the short notice.

Jul <var data-var='date'>18</var>, <var data-var='time'>04:00</var> MDT Completed - The scheduled maintenance has been completed. Jul <var data-var='date'>17</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Jul <var data-var='date'>10</var>, <var data-var='time'>10:03</var> MDT Scheduled - PSTN / Global SIP (Sansay Infrastructure): - Moving Sansay’s from old HK2 Rack to new HK2 Rack. ***Possible Impact: Active calls on the Hong Kong Sansay will be terminated when the maintenance begins. For any customers with functional redundancy from the Hong Kong Sansay to another CallTower datacenter will be able to make and receive new calls via the redundant datacenter during the maintenance window. Outage: Yes PSTN / Global SIP (Sansay Infrastructure): - LAX Border Router Software Updates ***Possible Impact: Sansay customer calls may intermittently drop while updates are being performed and traffic is rerouted. Outage: No Cisco: - Security Update Expressway Clusters for CUCM ***Possible Impact: *Cisco Jabber/ MRA Phones, Users will experience a connectivity loss with their Jabber Client/Services and/or MRA Edge connection Phones. Outage: Yes Legacy OneStream Customers: - car1ff reload/Licensing update. ***Possible Impact: All legacy OneStream voice services will be down for a few minutes while the device is being reloaded. Outage: Yes

Jul <var data-var='date'>16</var>, <var data-var='time'>12:31</var> MDT Resolved - Microsoft has reported that they have implemented a fix for the issue affecting Dial by Name functionality for Microsoft Teams customers. Following the deployment of the fix, CallTower engineers have completed validation testing across multiple customer tenants and have confirmed that the service is functioning as expected. If you are still experiencing issues, please reach out to support@calltower.com. CallTower will be closing this master case and all associated cases. Jul <var data-var='date'>15</var>, <var data-var='time'>13:01</var> MDT Update - CallTower engineers continue to work with Microsoft to investigate the Dial by Name issue affecting some Teams customers. The issue remains under active review, and escalation efforts are ongoing as both teams analyze available diagnostic information. We will share additional updates as soon as new information becomes available and thank you for your patience while this investigation continues. *CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 60 minutes, unless identified otherwise. This issue is being investigated as a top priority. Jul <var data-var='date'>15</var>, <var data-var='time'>11:43</var> MDT Update - CallTower engineers continue to investigate the issue affecting Dial by Name functionality for a subset of Teams Operator Connect customers. We remain actively engaged with Microsoft and continue to escalate the matter to assist in identifying the underlying cause and restoring normal service as quickly as possible. *CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 60 minutes, unless identified otherwise. This issue is being investigated as a top priority. Jul <var data-var='date'>15</var>, <var data-var='time'>10:39</var> MDT Investigating - CallTower is investigating reports of the Dial by Name feature not working for some of our Operator Connect customers. We have opened a case with Microsoft to help investigate this issue. *CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 60 minutes, unless identified otherwise. This issue is being investigated as a top priority.

Dial by Name Function Failing

Jul <var data-var='date'>13</var>, <var data-var='time'>08:51</var> MDT Resolved - CallTower considers the issue resolved at this time. We will be closing this master case and all associated cases. Within three business days, an Official Root Cause Analysis (RCA) or a Preliminary RCA will be available and provided to customers upon request. Jul <var data-var='date'> 9</var>, <var data-var='time'>06:02</var> MDT Monitoring - CallTower engineers have completed remediation efforts and service appears to be restored, based on current monitoring and testing. We ask that affected customers please retest their services and confirm that normal functionality has been restored. If you continue to experience any issues, please contact CallTower Support and provide details of the impact so that our teams can investigate further. CallTower has opened a master case for this issue as it is affecting more than one CallTower customer. This issue may or may not directly affect your services. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com as any new information becomes available. Jul <var data-var='date'> 9</var>, <var data-var='time'>05:33</var> MDT Update - CallTower Network Engineers have identified a potential cause of the service disruption and are actively working to implement remediation measures. At this time, our engineers are focused on validating the identified cause and restoring full-service stability as quickly as possible. We are continuing to monitor the environment closely and are treating this issue as a top priority. CallTower has opened a master case for this issue as it is affecting more than one CallTower customer. This issue may or may not directly affect your services. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise Jul <var data-var='date'> 9</var>, <var data-var='time'>05:00</var> MDT Identified - CallTower engineers are continuing their efforts to isolate and restore services in EMEA for all affected customers. CallTower has opened a master case for this issue as it is affecting more than one CallTower customer. This issue may or may not directly affect your services. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise Jul <var data-var='date'> 9</var>, <var data-var='time'>04:28</var> MDT Update - Microsoft Teams and Zoom customers in EMEA are receiving failures when attempting outbound calls. Calltower's voice network engineers have been engaged and are working diligently to restore services in EMEA. CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise. This issue is being investigated as a top priority. Jul <var data-var='date'> 9</var>, <var data-var='time'>03:57</var> MDT Investigating - CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise. This issue is being investigated as a top priority.

EMEA outbound calls failing

Jul <var data-var='date'>12</var>, <var data-var='time'>23:00</var> MDT Completed - The scheduled maintenance has been completed. Jul <var data-var='date'>12</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Jul <var data-var='date'>10</var>, <var data-var='time'>11:31</var> MDT Scheduled - Purpose: Patching and preventative maintenance on multiple systems. Systems Affected: CT Cloud Voice: - Meta WAFs - Modify WAF Inspection ***Possible Impact: Users may need to log back into CommPortal and/or CT Cloud Communicator

Jul <var data-var='date'> 7</var>, <var data-var='time'>17:10</var> MDT Completed - The scheduled maintenance has been completed. Jul <var data-var='date'> 7</var>, <var data-var='time'>15:45</var> MDT Scheduled - As part of our ongoing efforts to protect customers from toll fraud, CallTower is expanding the list of high-risk calling destinations to include select exchanges in Alaska and Montana. Customers who do not have high-risk calling enabled on their account may be unable to place calls to certain destinations identified as having an elevated fraud risk. If you are unable to complete calls to a destination and believe there is a legitimate business need, please contact CallTower Support. Our team can help determine whether fraud-prevention controls are affecting call completion and discuss available options.

Service Update: High-Risk Calling Destination Changes

May <var data-var='date'>16</var>, <var data-var='time'>04:00</var> MDT Completed - The scheduled maintenance has been completed. May <var data-var='date'>15</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. May <var data-var='date'> 8</var>, <var data-var='time'>09:22</var> MDT Scheduled - Cisco: - Update mra.ct450.com and mra-02.ct450.com latest release ***Possible Impact: Cisco Edge Phones: CallTower will be loading a Public Certificate to all Edge servers for mra.ct450.com and mra02.ct450.com . Phones are expected to be down for no more than a few minutes and should connect as usual once servers are restarted. Outage: No Webex: - car1.lon & car1.fra cleanup ***Possible Impact: Webex customers may experience brief interruption of active calls when changes are made Outage: No Fax: - MasterFax - Isolate MP202B traffic ***Possible Impact: Some MasterFax ATAs may experience a brief interruption as devices reconnect to our Fax Servers during the Maintenance Window Outage: Yes ATL Meta Customers: - ATL Meta - May 2026 maintenance ***Possible Impact: New calls may fail to setup while services are failed over during maintenance. Calls in progress will not be affected. Downtime will be 30 seconds or less. Outage: Yes CT Cloud Communicator: - CT Cloud Communicator Mobile 3.21.61 ***Possible Impact: CT Cloud Communicator Mobile users will be forced to upgrade to v3.21.61 to continue using the application. As a reminder, users currently using CTCC mobile pre-3.21.61 must perform a one-time manual upgrade, or in-app upgrades will fail. Additional information about this is available in uc.solutions. Outage: No

Apr <var data-var='date'>29</var>, <var data-var='time'>12:59</var> MDT Resolved - CallTower Support has confirmed resolution of the Five9-related issues that were impacting call delays, audio issues, browser speed, and connection issues to Five9. The issue was addressed in coordination with Five9 Engineering, and services are operating normally at this time. CallTower will be closing this master case and all associated cases. Within three business days, an Official Root Cause Analysis (RCA) or a Preliminary RCA will be available and provided to customers upon request. Apr <var data-var='date'>29</var>, <var data-var='time'>11:22</var> MDT Investigating - CallTower Support has received reports of issues impacting some Five9 customers. Users may experience call delays, Audio issues, intermittent slow browser speed, and connection issues to Five9. CallTower support is currently investigating with Five9 engineering to mitigate and resolve these issues. *CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 60 minutes, unless identified otherwise. This issue is being investigated as a top priority.

Five9 Service Degradation – Call Performance and Connectivity Issues

Mar <var data-var='date'>23</var>, <var data-var='time'>00:00</var> MDT Completed - The scheduled maintenance has been completed. Mar <var data-var='date'>22</var>, <var data-var='time'>20:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Mar <var data-var='date'>17</var>, <var data-var='time'>14:27</var> MDT Scheduled - Purpose: Patching and preventative maintenance on multiple systems. Systems Affected: CT Cloud Voice: -ATL Meta - March 2026 maintenance ***Possible Impact: New calls may fail to set up while services are failed over during maintenance. Calls in progress will not be affected. Downtime will be 30 seconds or less.

Mar <var data-var='date'>21</var>, <var data-var='time'>04:00</var> MDT Completed - The scheduled maintenance has been completed. Mar <var data-var='date'>20</var>, <var data-var='time'>22:00</var> MDT In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Mar <var data-var='date'>13</var>, <var data-var='time'>11:32</var> MDT Scheduled - Purpose: Patching and preventative maintenance on multiple systems. Systems Affected: Fax: -MasterFax and CT Cloud Fax - General Server Maintenance ***Possible Impact: Customers will experience interruptions to both MasterFax and CT Cloud Fax services during the Maintenance Window Cisco: -Update mra.ct450.com and mra02.ct450.com Latest Release ***Possible Impact: Cisco Edge Phones: CallTower will be loading a Public Certificate to all Edge servers for mra.ct450.com and mra02.ct450.com . Phones are expected to be down for no more than a few minutes and should connect as usual once servers are restarted.

Mar <var data-var='date'> 2</var>, <var data-var='time'>13:15</var> MST Resolved - CallTower Support has received positive confirmation from affected customers, and the CT Cloud Communicator Mobile issue is considered resolved. CallTower will be closing this master case and all associated cases. Within three business days, an Official Root Cause Analysis (RCA) or a Preliminary RCA will be available and provided to customers upon request. Mar <var data-var='date'> 2</var>, <var data-var='time'>12:37</var> MST Monitoring - Based on vendor guidance, CallTower Engineering completed a configuration change designed to address the CT Cloud Communicator Mobile issue. CallTower Support will continue to monitor the environment to confirm the issue is fully resolved. CallTower has opened a master case for this issue as it is affecting more than one CallTower customer. This issue may or may not directly affect your services. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise. Mar <var data-var='date'> 2</var>, <var data-var='time'>11:32</var> MST Update - CallTower Engineering continues to partner with the vendor on log and diagnostic review. The issue has been isolated to an affected system, and investigation is ongoing. CallTower has opened a master case for this issue as it is affecting more than one CallTower customer. This issue may or may not directly affect your services. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise. Mar <var data-var='date'> 2</var>, <var data-var='time'>10:56</var> MST Update - CallTower Engineering remains engaged with the vendor and is providing logs and diagnostic information as part of the ongoing resolution process. CallTower has opened a master case for this issue as it is affecting more than one CallTower customer. This issue may or may not directly affect your services. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise. Mar <var data-var='date'> 2</var>, <var data-var='time'>10:25</var> MST Identified - The issues affecting CT Cloud Communicator Mobile have been identified as vendor-related. CallTower engineers are actively working with the vendor to determine and implement a resolution. CallTower has opened a master case for this issue as it is affecting more than one CallTower customer. This issue may or may not directly affect your services. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise. Mar <var data-var='date'> 2</var>, <var data-var='time'>09:52</var> MST Investigating - CallTower Support is actively investigating multiple reports of inbound and outbound call failures and login issues with CT Cloud Communicator Mobile but has not identified/confirmed there is an issue on our network or with our services. CallTower has opened a master case to investigate this issue as it has been reported by more than one CallTower customer. This issue may or may not directly affect your services and is currently under investigation. If you are affected, please report the issue to support@calltower.com. CallTower intends to post updates on status.calltower.com approximately every 30 minutes, unless identified otherwise. This issue is being investigated as a top priority.

CT Cloud Communicator Mobile Inbound calls, Outbound calls, and Login Issues

Mar <var data-var='date'> 1</var>, <var data-var='time'>23:00</var> MST Completed - The scheduled maintenance has been completed. Mar <var data-var='date'> 1</var>, <var data-var='time'>21:00</var> MST In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Feb <var data-var='date'>27</var>, <var data-var='time'>10:33</var> MST Scheduled - Purpose: Patching and preventative maintenance on multiple systems. Systems Affected: CT Cloud Voice: -CT Cloud Maintenance - March 2026 ***Possible Impact: New calls may fail to set up while services are failed over during maintenance. Calls in progress will not be affected. Downtime will be 30 seconds or less.

Feb <var data-var='date'>23</var>, <var data-var='time'>02:00</var> MST Completed - The scheduled maintenance has been completed. Feb <var data-var='date'>22</var>, <var data-var='time'>20:00</var> MST In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Feb <var data-var='date'>13</var>, <var data-var='time'>10:24</var> MST Scheduled - CT Cloud Maintenance - February 2026 Purpose: Upgrade CHI/DAL Meta from 9.6.70 to 9.7.20 Systems Affected: CT Cloud SIP CT Cloud Voice Impact: New calls may fail to setup while services are failed over during maintenance. Calls in progress will not be affected. Downtime will be 30 seconds or less. Outage: Yes NOAM Meta 9.7 upgrade Purpose: Upgrade CHI/DAL Meta to 9.7.20 SU13 for security and stability improvements. Systems Affected: CT Cloud SIP CT Cloud Voice Impact: New calls may fail to setup while services are failed over during maintenance. Calls in progress will not be affected. Downtime will be 30 seconds or less. Outage: Yes

Feb <var data-var='date'>21</var>, <var data-var='time'>03:00</var> MST Completed - The scheduled maintenance has been completed. Feb <var data-var='date'>20</var>, <var data-var='time'>21:00</var> MST In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary. Feb <var data-var='date'>13</var>, <var data-var='time'>10:22</var> MST Scheduled - ATL Data Center Core Switch Maintenance Purpose: replace the main core switch in the ATl Data Center Systems Affected: Cisco Jabber Cisco Voice Impact: Cisco Jabber: Jabber clients may experience intermittent connectivity or login issues as servers are shutdown and failover to redundant data centers occurs. Cisco phone registration: Cisco phones may temporarily unregister as they reregister with servers in redundant data centers. Outage: No MasterFax & CT Cloud Fax - General Server Maintenance Purpose: Monthly server maintenance: remove old/stuck faxes, reboot servers updating Wireshark Systems Affected: MasterFax CT Cloud Fax Impact: Customers will experience interruptions to both MasterFax and CT Cloud Fax services during the Maintenance Window Outage: Yes Update Jabber certificate for collaborate-atl.ct450.com Purpose: Calltower will be upgrading the Edge servers for Jabber. Systems Affected: Cisco Jabber Impact: Users will experience a connectivity loss with their Jabber Client/Services. Outage: Yes

Feb <var data-var='date'>20</var>, <var data-var='time'>12:15</var> MST Resolved - Some CallTower customers may have briefly experienced issues with Intermedia Contact Center Voice and login. The issue was identified as an Intermedia service outage and has since been resolved. Update from Intermedia: Intermedia Engineering teams identified the root cause as a Cloudflare service disruption that affected connectivity to certain Intermedia services. The third-party provider has since restored service, and Intermedia has verified that Email, Contact Center, and Voice services are fully operational. If any issues persist, customers are advised to contact Intermedia Support for assistance. CallTower will be closing this master case and all associated cases. Within three business days, an Official Root Cause Analysis (RCA) or a Preliminary RCA will be available and provided to customers upon request.

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