Cisco VG2044-Port Analog Telephone Adapter FXS VoIP Gateway SIP

Key Benefits

• 4 x FXS analog ports: Connect up to 4 analog phones, fax machines, or DECT bases directly to a VoIP network — enabling gradual migration from PSTN without replacing handsets.
• SIP and H.323 protocol support: Compatible with major VoIP platforms including Cisco Unified Communications Manager, Asterisk, FreePBX, and third-party SIP PBX systems.
• Cisco IOS Voice operating system: The same trusted IOS platform used across Cisco's enterprise voice portfolio — reliable, feature-rich, and familiar to Cisco-trained administrators.
• Fax and modem support: T.38 fax relay and G.711 pass-through ensure reliable fax transmission over IP networks without dedicated PSTN fax lines.
• Compact desktop form factor: Small enough to sit on a desk or in a comms cabinet — no rack space required. Ideal for small offices and branch sites.
• Certified refurbished with 12-month warranty: Professionally tested and graded by Reboot IT — Melbourne's enterprise networking specialists since 2001.

Performance in Use

The Cisco VG204 solves one of the most common VoIP migration challenges: what to do with existing analog phones and fax machines when moving to an IP telephony system. With 4 FXS ports, it acts as the interface between the analog world and your VoIP infrastructure — registering each port as a SIP extension on your PBX and presenting a standard phone jack to the connected device. Analog handsets, fax machines, DECT bases, and modems all plug in and function as if still connected to a traditional phone line.

Running Cisco IOS Voice, the VG204 supports dial plan configuration, codec selection (G.711, G.729), DTMF relay, and call progress tone generation for Australian PSTN compatibility. T.38 fax relay handles fax-over-IP transmission reliably — a common pain point with VoIP gateways that use G.711 pass-through only. Integration with Cisco Unified Communications Manager Express (CME) or CUCM allows the gateway to be managed within the broader Cisco UC framework.

For small offices with a mix of IP phones and legacy analog devices, the VG204 eliminates the need to maintain a separate PSTN connection solely for fax or a few analog handsets. Branch offices in a hub-and-spoke UC deployment can use it to provide local analog extensions without separate PBX hardware at each site.

Tech Specs

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Frequently Asked Questions

What is the difference between FXS and FXO ports?

FXS ports (on the VG204) connect to analog phones and fax machines — the gateway provides dial tone and ring voltage. FXO ports connect to PSTN phone lines. The VG204 has FXS only, so it connects analog devices to your VoIP network but cannot directly terminate PSTN lines.

Is it compatible with Asterisk or FreePBX?

Yes — the VG204 supports standard SIP registration and can register its FXS ports as extensions on any SIP-compatible PBX including Asterisk, FreePBX, 3CX, and other open-source or commercial systems.

Does it support reliable fax transmission over VoIP?

Yes — the VG204 supports T.38 fax relay, which is the recommended protocol for reliable fax over IP. This avoids the packet loss sensitivity that affects G.711 fax pass-through and significantly improves fax success rates over VoIP.

Can I use it with Cisco Unified Communications Manager?

Yes — the VG204 integrates with Cisco CUCM and Cisco CME for enterprise deployments, supporting MGCP and H.323 protocols in addition to SIP. Configuration is via Cisco IOS CLI or web interface.

Do I need more than 4 ports?

If you need more than 4 analog ports, consider the Cisco VG224 (24 FXS ports) or VG310/VG320 series for higher-density deployments.

What shipping costs apply?

Shipping costs apply based on size and destination — rates are calculated at checkout.