Fritz!Box as Router for Fiber and DSL (2025): Models, Compatibility and Setup Options

Many households face the same question in 2025: Which Fritz!Box is suitable as a router for fiber connections, and which model remains flexible as a DSL router if switching to FTTH later? From my tests and installations in FTTH and DSL environments, I've compiled the most important points here – with clear recommendations, compatibility details and realistic topologies.

Model Overview 2025: Fritz!Box for Fiber and DSL

For 2025, a clear model split is emerging: FTTH models like the Fritz!Box 5530 Fiber and 5590 Fiber support fiber directly via SFP. DSL routers like the Fritz!Box 7590 AX or 7530 AX score with integrated DSL modem (ADSL2+/VDSL2 incl. supervectoring). Pure WAN routers like the Fritz!Box 4060 are ideal behind ONT/media converters – very flexible for FTTH and migrations.

When selecting, you should compare three factors: connection type (FTTH/DSL), port requirements (1G/2.5G, number of LAN) and telephony (DECT base, analog/ISDN connections). AVM consistently uses WLAN 6 (ax), sometimes tri-band, and mesh is widely available – important for large apartments and houses.

If you want to decide quickly, read my favorite comparison: [url="https://www.siio.de/quack/4718/fritzbox-5590-vs-7590ax-mit-modem—was-ist-besser/",name="Fritz!Box 5590 vs. 7590 AX: What is better?",title="Comparison 5590 vs 7590 AX"] – I show clear use cases there. Those who want to buy directly will find a suitable source here: [asin="B09ZD4LFR3",type="standard"].

Fiber Compatibility: SFP/ONT and Standards

FTTH in Germany/Austria/Switzerland usually runs as AON (Active Ethernet) or GPON (Passive Optical Network). The Fritz!Box 5530/5590 Fiber support – module dependent – both variants. The deciding factor is whether your provider provides or releases a suitable SFP module. Alternatively, the Fritz!Box can also be operated behind an ONT via Ethernet WAN (here 4060, 7590 AX, 7530 AX are flexible).

I like to operate FTTH installations behind the ONT: The PON registration and signal parameters remain with the provider device, and I can cleanly configure VLAN ID, PPPoE/DHCP and other access data on the Fritz!Box. For direct connection via SFP: Pay attention to provider releases, Serial/LOID/OMCI parameters (GPON) and whether the provider allows own devices.

DSL Operation: Profiles and Access

As DSL routers, 7590 AX and 7530 AX are proven. They master ADSL2+/VDSL2 with supervectoring 35b (model dependent) and work reliably in my tests on typical DSLAM profiles. For dial-in, PPPoE access data is usually required; with Annex J, the Fritz!Box can often automatically recognize line parameters.

Those migrating from DSL to FTTH simply use the Fritz!Box at the WAN port behind ONT. The trick: With config export/import (FRITZ!OS), telephony entries, WLAN keys and port forwards are largely preserved. Especially in the SoHo area, this saves me a complete reconfiguration.

Setup Options and Topologies

Depending on infrastructure, three setups have proven themselves in practice:

1. Direct at fiber connection (SFP): 5530/5590 Fiber with suitable AON/GPON module. Advantage: Fewer devices, no ONT power consumption. Disadvantage: Dependent on provider releases.
2. Behind ONT/media converter via WAN: 4060, 7590 AX or 7530 AX. Advantage: Very compatible, simple provider handling. 4060 shines with 2.5G WAN and strong WLAN.
3. Migration DSL → FTTH: Existing 7590 AX remains, WAN port to ONT, import config, adjust VLAN/PPPoE. Fast, safe, with minimal outages.

For large apartments/houses I use FRITZ! Mesh with repeaters as backhaul. Those who use tri-band (e.g. 4060) keep the mesh more stable because one band remains free for the backhaul connection.

Telephony and Smart Home

AVM traditionally delivers strong telephony features: DECT base for handsets, integrated answering machines, SIP trunk support and – model dependent – analog/ISDN ports. Number porting via SIP works smoothly in my tests, fax via T.38 is available, but in IP environments always depends on the counterpart.

In the smart home area, FRITZ!DECT actuators (e.g. switching sockets, radiator thermostats) and door intercoms (via a/b or SIP) can be integrated. Standard features are sufficient for simple automations; I realize more complex scenarios via external systems and connect the Fritz!Box via VPN or dedicated VLAN.

Provider Profiles in DE/AT/CH

Important are the VLAN/PPPoE profiles: VLAN 7 is frequently used in Germany by Telekom (especially VDSL/FTTH profiles). Other providers use other VLANs or DHCP without PPPoE. In Switzerland I often see DHCP with VLAN tagging (e.g. VLAN 10) – the Fritz!Box can be adapted to this. In Austria it varies by network operator, which is why I check the official provider profiles or activation lists.

IPv6 is also standard, sometimes with DS-Lite. Business tariffs more often provide static IPs or prefix delegation with stable prefixes. Those who don't want to use TR-069 can deactivate provisioning and configure everything manually.

Performance, Security and Management

Depending on the model, I realistically achieve 600–1200 Mbit/s net in WLAN on modern devices (Wi-Fi 6, 80 MHz). Decisive are the antenna configurations (2×2, 4×4), the interference environment and whether tri-band is available. For wired clients I recommend 2.5G ports (5590/5530/4060), so that 1–2 Gbit/s connections don't hang on the LAN bottleneck.

FRITZ!OS shines in 2025 with stable updates (7.6x), auto backup, optional TR-069, WireGuard and IPsec VPN. For QoS, the means are sufficient in the home area: prioritization for home office, guest network with bandwidth limit and clean port forwards are quickly set. USB functions (NAS, printer, mobile fallback) work solidly, even though dedicated NAS delivers better performance.

My experience: The 4060 behind ONT is currently the most flexible way for FTTH households that value strong WLAN and 2.5G. Those who want "all-in-one" will be happy with the 5590 Fiber – provided the provider releases the appropriate SFP/profile.

Troubleshooting and Best Practices

• Check LEDs: In SFP operation, pay attention to LOS/Link status; in GPON check registration status. Behind ONT, the Ethernet link LED should be stable.
• MTU/PPPoE: With PPPoE test MTU 1492; with IPoE/DHCP usually 1500. Avoid fragmentation.
• VLAN tagging: Set VLAN ID exactly according to provider. If unclear, first test without VLAN (some networks tag at ONT).
• Avoid double NAT: Switch ONT/provider box to bridge or Fritz!Box as exposed host – better: real bridge/pass-through profile.
• Fallback internet: Stay online temporarily via LTE/5G USB stick or phone tethering; then check logs (System/Events).
• Build mesh cleanly: Connect repeaters via LAN or tri-band, identical SSIDs only within one network, don't overload channels.

• help

  Which Fritz!Box is the best choice with unclear FTTH profile?

  Put the Fritz!Box behind the ONT (e.g. 4060 or 7590 AX at WAN). This way the PON profile doesn't matter, and you remain flexible when changing providers.

• help

  Can I use my DSL Fritz!Box later on fiber connection?

  Yes. The 7590 AX/7530 AX can be connected directly to the ONT via WAN port. Set up PPPoE/DHCP and VLAN ID according to provider, import configuration – done.

• help

  What to watch for with telephony (SIP) on FTTH?

  Take over provider data exactly, set UDP timeouts and NAT keepalive correctly. If problems occur, deactivate/activate STUN and test codec priorities.

• help

  Is 2.5G worth it in home networks already?

  With tariffs from 1 Gbit/s and NAS/workstations yes. At least the uplink port (router ↔ switch) should be capable of 2.5G, otherwise 1G limits.

If you can't decide between FTTH and DSL setup, I recommend the practical comparison: [url="https://www.siio.de/quack/4718/fritzbox-5590-vs-7590ax-mit-modem—was-ist-besser/",name="Fritz!Box 5590 vs. 7590 AX",title="Comparison 5590 vs 7590 AX"]. And if you want to order directly, this widget helps you: [asin="B09ZD4LFR3",type="standard"].

My recommendation summarized:

• FTTH today: 5590 or 5530 Fiber (SFP, if released) – alternatively 4060 behind ONT.
• DSL today, FTTH tomorrow: Keep 7590 AX and later reuse via WAN at ONT; or 4060 + modem/ONT.
• Large home network: Pay attention to 2.5G uplinks and mesh with tri-band.