WikiDevi.Wi-Cat.RU:DD-WRT/Linking Routers/Repeating Mode Comparisons

WDS vs R (Repeater) vs RB (Repeater Bridge)

This is a summary of issues related to repeating using "WDS" vs "Repeater" vs "Repeater Bridge" modes. Please note that some lines still require confirmation ("TODO: Confirm"). If you experiment and your results differ from those indicated here, please add comments providing your HW and DD-WRT version.

• On both WDS and R/RB (both R and RB), the repeater and base can broadcast different SSIDs.
  • On WDS with WPA, both routers need to have the same SSID (TODO: Confirm).
  • On WDS, both routers need to have the same SSID, which will be broadcast by both routers (TODO: Confirm).
  • On R/RB, the base SSID will not only be used for joining the main-router, but also be repeated by the repeater (TODO: Confirm).
  • On R, two SSIDs with the same name will collide (give problems) (TODO: Confirm). On RB, having the same SSID on the main-router and the repeater allows "roaming", ie. keeping a connection active ¿or reconnect? (TODO: CONFIRM) when a client switches to another router.
  • After RC6.2, virtual interfaces have BSSID with MAC address 02:XX:XX:XX:XX:01 for R mode. If the main-router and the repeater broadcast a BSSID with the same MAC, they probably will collide. For RB mode the MAC address is 00:XX:XX:XX:XX:01. - redhawk
• WDS and R/RB both will reduce effective bandwidth in half for all wireless clients (but not for wired clients). Wireless repeating means that each packet is repeated, ie re-transmitted, thereby taking twice as much air time.
• WDS must be configured on both routers (requires access) and requires a compatible WDS implementation. R/RB only needs to configure the repeater and doesn't rely on the main-router's HW or firmware version.
• WDS can support WEP, WPA, and WPA2 Personal (TKIP+AES) as of v24sp1 (and earlier?). [tested with wrt150n1.1 AP + wrt54g6 R] (TODO: test other hardware). R/RB support all encryption algorithms.
• WDS supports building a network of routers, where each repeater can connect to multiple other "main-routers" (WAN-routers) at the same time (TODO: Confirm). R/RB only connects to one router at a time, by SSID. Both WDS and R support connecting multiple repeaters in series ("repeat a repeater"), however a RB must connect to a DHCP serving unit (UPDATE - it is now possible to connect and RB through another RB unit now svn11296 tested 01/09/09- redhawk) (TODO: Clarify - does this have anything to do with DHCP, or does it mean "each RB will only connect to a wired (non-repeating) AP"? Clarification: Yes it has something to do with DHCP. It will connect to a regular repeater (R) just fine. See here for further info.)
• WDS does not perform MAC address translation (MAT). R/RB does translate MACs : the main-router sees all connections from clients which connects through the repeater belonging to the same MAC as the repeater. This causes problems with some applications which rely on a MAC address.

I'm still confused! Which mode should I use?

The following are just some general guidelines for helping you choose the proper repeater mode.

• Use WDS if
  • you have control over all routers and they each have compatible WDS implementations.
  • you want to repeat your wireless signal and/or connect multiple networks together.
• Use R (Repeater) if
  • you don't have control over the host access point/router.
  • you want to repeat a wireless signal coming from your ISP.
  • you're staying at a hotel and want to boost an otherwise weak wireless signal to your laptop.
• Use RB (Repeater Bridge) if
  • your host router/access point doesn't support WDS.
  • you want to repeat a wireless signal and have all clients on the same network (same subnet).

Repeating Mode Comparison Table

	WDS	Client Mode	Client Bridge	Repeater	Repeater Bridge	Two routers (1 Client Mode, 1 AP Mode)
Requires admin control over all routers, and the routers must have compatible WDS implementations	•
Does not require control over host access point/routers; can connect to a host you don't control		•	•	•	•	•
Supports multiple wired client devices	•	•	• *	•	• *	•
Supports multiple wireless client devices	•			•	• *	•
Bandwidth is halved for wireless clients	•	n/a	n/a	•	•	Not if you use two channels
All routers and clients share the same subnet	in LAN mode		•		•
Each router is on its own subnet with its client devices	in P2P mode	•		•		•
Creates a true transparent bridge compatible with all protocols	•
Uses MAC address translation (MAT) (proxy ARP) (not compatible with some applications and protocols that depend on MAC addresses) (potential ARP problems) *			• *		• *
Allows different SSID on repeated network	depends on encryption choice	n/a	n/a	•	•	•
Encryption support	WEP, WPA (caveats)	any	any	any	any	any
Can repeat signal from a wireless ISP				•	•	•
Can repeat a weak wireless signal in a hotel		•		•	•	•

* As some problems only surface when multiple client devices are connected, having only one client device is a way to resolve some compatibility issues.

See Also

Linking Routers