Source record · tier 2 current vendor documentation

Site survivability for Webex Calling

Publisher: Cisco Webex
URL: https://help.webex.com/en-us/article/d68vi1/Site-survivability-for-Webex-Calling
Published: 2026-07-06
Updated: unknown
Accessed: 2026-09-24
HTTP status: 200
License: Cisco documentation; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

Basic Automatic Call Distribution (B-ACD) is not supported when the Survivability Gateway is colocated with a Local Gateway. in context
Maximum endpoint registrations on the Survivability Gateway are 50 on an ISR 4321 and 100 on an ISR 4331 and 700 on an ISR 4351. in context
Maximum endpoint registrations on the Survivability Gateway are 1200 on an ISR 4431 and 2000 on an ISR 4451-X or 4461 and 2500 on a Catalyst 8200-1N-4T and 2000 on a large Catalyst 8000V. in context
After assignment, a Download Config Template action on the gateway details page in Control Hub provides a reference configuration for the gateway. in context
A daily call data sync from the Webex cloud to the Survivability Gateway carries authentication information for registered users and their routing information. in context
The Webex cloud includes the Survivability Gateway IP address, hostname and port in each endpoint's device configuration file so endpoints can register to it during an outage. in context
Dialing patterns can work differently in Survivability mode than in Active mode. in context
Emergency calls in Survivability mode go out with the ELIN defined for an Emergency Response Location, configured with voice emergency response location (elin and subnet) and voice emergency response zone. in context
Survivability-capable endpoints include Cisco MPP phones on firmware 12.0(1) or later (6800 and 7800 and 8800 series), 9800 series on PhoneOS 3.2(1) or later, Webex App for Windows and Mac 43.2 or later, and VG400/410/420 and ATA 191/192 adapters. in context
Before configuring Site Survivability the gateway must be enrolled to the Webex cloud as a Cisco IOS managed gateway. in context
Registrations and call control revert to the Webex cloud once the Webex network connection has been restored for at least 30 seconds. in context
The Survivability Gateway supports up to 100 hunt groups of at most 32 users each using sequential, parallel, peer or longest-idle algorithms; weighted routing is not supported. in context
The Survivability Gateway routes internal calls automatically using routing information from Webex, and a PSTN trunk configuration must be added to it to provide external calling. in context
Hunt Group, Call Forward and Auto Attendant features on the Survivability Gateway require IOS XE 17.18.2 or later. in context
Webex Calling Survivability Gateway features are available with Cisco IOS XE Dublin 17.12.3 or later releases. in context
The Survivability Gateway must use an IPv4 address; IPv6 is not supported. in context
A Catalyst edge platform Survivability Gateway requires a DNA Network Advantage feature license or better plus a throughput license. in context
An ISR 4000 series Survivability Gateway requires the uck9 and securityk9 boot-level licenses. in context
Devices with 4G or 5G connectivity may stay registered to Webex Calling during a site outage and may be unable to call other numbers at the same site location. in context
The mode webex-sgw command under voice register global enables Webex Calling Survivability mode and makes the gateway listen on port 8933 for incoming secure (TLS) connections. in context
One Survivability Gateway can be assigned to multiple locations by selecting all required locations in the assignment dialog, for multiple smaller locations within the same LAN. in context
Configuring the SIP bind command in voice service voip configuration mode on the Survivability Gateway causes MPP phone registration to the gateway to fail. in context
The Survivability Gateway does not support wildcard certificates. in context
Supported Survivability Gateway platforms include the ISR 4000 series (4321 to 4461), Catalyst 8200 and 8300 edge platforms, and the virtual ISRv and Catalyst 8000V. in context
PSTN service availability in Survivability mode depends on the SIP trunks or PSTN circuits available during the network outage. in context
PSTN access for the Survivability Gateway is configured either through a voice interface card connected directly to the PSTN or through a SIP trunk to a PSTN gateway or provider. in context
The documented SIP trunk example uses voice class tenant 300 with a sip-server target and bind to the PSTN-facing interface, and an outbound dial-peer 300 with session target sip-server, voice-class sip tenant 300, a codec class and dtmf-relay rtp-nte. in context
The Survivability Gateway supports only certificates from publicly known certificate authorities; private or enterprise CA certificates cannot be used. in context
When a site loses its connection to the Webex cloud, supported endpoints automatically switch to Survivability mode and register with the local Survivability Gateway, which provides fallback calling. in context
The Survivability Gateway certificate key must be RSA with a minimum size of 2048 bits. in context
B-ACD sessions on the gateway can be checked with show call application sessions and hunt group activity with show voice hunt-group statistics. in context
Each site that deploys Site Survivability requires a Survivability Gateway within its local network. in context
An on-demand sync is started with the Sync button on the gateway in Control Hub and may take up to 10 minutes to complete. in context
The status update for an on-demand sync can take up to 30 minutes to appear in Control Hub. in context
Third-party devices are not supported with the Survivability Gateway. in context
The gateway certificate is created under crypto pki trustpoint webex-sgw with fqdn and subject-name and subject-alt-name set to the gateway FQDN, which must match the Host Name entered in Control Hub; the CA-signed certificate is then enrolled, authenticated and imported with crypto pki enroll, authenticate and import. in context
In Survivability mode conferencing and three-way calling are not supported, and the Park, Unpark, Barge and Pickup softkeys are not supported although they do not appear disabled on the phone. in context

Cite this source record

APA

WarmTransfer. (2026, July 6). Site survivability for Webex Calling. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-help-d68vi1-site-survivability-b

BibTeX

@misc{warmtransfer-cisco-help-d68vi1-site-survivability-b,
  title  = {Site survivability for Webex Calling},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-help-d68vi1-site-survivability-b},
  note   = {Cisco Webex, accessed 2026-09-24}
}