Cisco GRWIC-ISDN-1B-S/T Cisco network interface module
Brand: Cisco | Category: Accessories & Components
SKU: CSC-GRWIC-ISDN-1B-ST | Part #: GRWIC-ISDN-1B-S/T | MPN: GRWIC-ISDN-1B-S/T
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About the Cisco GRWIC-ISDN-1B-S/T Cisco network interface module
Accessories in production networks demand rapid replacement cycles—the Cisco GRWIC-ISDN-1B-S/T delivers carrier-grade ISDN connectivity as a field-swappable module for enterprise branch offices requiring dial backup and legacy circuit resilience. This genuine Cisco network interface module (part number GRWIC-ISDN-1B-S/T) is a single-wide GRWIC (Gigabit Router WAN Interface Card) engineered for Cisco ISR G2 platforms where on-demand WAN failover and ISDN dial protocols remain critical infrastructure components. Network engineers deploying hybrid WAN architectures will recognize the value of native Cisco IOS support for DDR (dial-on-demand routing), dial backup, and full ISDN protocol stacks, eliminating the performance tax of third-party gateways.
The module provides one ISDN BRI S/T interface operating at the ITU-T standards: I.430 (Physical Layer), Q.921 (Data Link), and Q.931 (Network Layer). This configuration delivers a single 64 Kbps bearer channel (B-channel) plus one 16 Kbps signaling channel (D-channel), with a maximum bearer data rate of 64 Kbps per connection. Termination is via RJ-45 connector at the S/T reference point (four-wire), requiring an external NT1 device—not included with the module. Genuine Cisco hardware validation is mandatory for Cisco TAC support eligibility, making OEM sourcing non-negotiable for production environments.
Deployment Scenarios
- Branch office dial-backup for Cisco ISR G2 1900, 2900, and 3900 series routers during primary link failure
- Legacy ISDN circuit integration in hybrid networks where carrier infrastructure remains active
- Redundant signaling and low-bandwidth failover for remote sites with limited WAN options
- DDR activation and protocol negotiation via native Cisco IOS without external appliances
- Cost-effective carrier circuit utilization for scheduled backup and disaster recovery workflows
Contact Omnixon Global to request a quotation for the Cisco GRWIC-ISDN-1B-S/T module and confirm availability for your ISR deployment.
Technical Specifications
| Brand | Cisco |
| Category | Accessories & Components |
| SKU | CSC-GRWIC-ISDN-1B-ST |
| Part Number | GRWIC-ISDN-1B-S/T |
| Condition | New |
| Interface | ISDN |
| Manufacturer Part Number | GRWIC-ISDN-1B-S/T |
| Module Type | GRWIC (Gigabit Router WAN Interface Card) |
| Form Factor | GRWIC (single-wide) |
| Compatible Platforms | Cisco ISR G2 1900, 2900, 3900 series (GRWIC slot) |
| Number of WAN Ports | 1 |
| Interface Type | ISDN BRI S/T |
| Physical Reference Point | S/T (four-wire, requires external NT1) |
| ISDN Standard | ITU-T I.430 (Physical Layer), Q.921 (Data Link), Q.931 (Network Layer) |
| Bearer Channels (B-channels) | 1 x 64 Kbps |
| Signaling Channel (D-channel) | 1 x 16 Kbps |
| Maximum Bearer Data Rate | 64 Kbps |
| Connector Type | RJ-45 |
| Software Support | Cisco IOS (DDR, dial backup, ISDN protocols) |
| NT1 Inclusion | Not included — external NT1 required |
| Product Line | Cisco ISDN Interface Modules |
| Genuine Cisco Hardware | Yes — required for Cisco TAC support validation |
Frequently Asked Questions about Cisco GRWIC-ISDN-1B-S/T Cisco network interface module
What does the Cisco GRWIC-ISDN-1B-S/T Cisco network interface module do?
The Cisco GRWIC-ISDN-1B-S/T Cisco network interface module is enterprise IT hardware deployed in production data centers, server rooms, and edge sites across the GCC and EMEA region.