If the LAN port of a wireless access point is 100 Mbps, then what is the need of 150 Mbps wireless speed? Why do they give 150 Mbps wireless speed?
asked Feb 12, 2016 at 7:15
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Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.– Ron Maupin ♦Commented Aug 7, 2017 at 18:55
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2 Answers
Virtually all professional WAPs (what are on topic on this site) have 1 Gbps ethernet ports.
A WAP is a translating bridge, it translates from ethernet to Wi-Fi and back. You need to understand that you have two different, independently-developed technologies being bridged. One technology, ethernet, has standards for different speeds (10 Mbps, 100 Mbps, 1000 Mbps, and 10,000 Mbps) on UTP. Each bump in speed costs more, and it took some years between bumps in speed. On the other hand, Wi-Fi was developed for its medium (radio), and it has multiple standards, each with its own maximum theoretical speed. Because of real-world obstacles, it is unlikely that you can get anywhere near the theoretical maximum speed on a WAP. To bridge these disparate technologies, you need to use what each technology offers and balance the price/performance ratio, otherwise your product won't sell.
answered Feb 12, 2016 at 7:40
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To complete the answer, vendors are selling 1.3 Gbps APs in channel radio with 1Gb Ethernet ports. As @Ron said, different technologies different standards.– KorXoCommented Feb 12, 2016 at 8:01
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@KorXo, Cisco is now using something new to let 1 Gbps ethernet be bundled or use a new 2.5 Gb connection on some switches. It's about to get confusing.– Ron Maupin ♦Commented Feb 12, 2016 at 8:03
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only option I made up is make a port channel in ethernet ports (in the case the AP had 2x1Gb ports) so theorical 1.3 Gbps radio can be handle in the 2Gb channel. Don't hear about another solution from Cisco. Could you provide more info about it?– KorXoCommented Feb 12, 2016 at 8:12
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I don't have anything available right now, and I'm not really involved in the wireless side of things, but I sat in on a few briefings Cisco gave us on some switches last year. There is something going on with the 45xx switches regarding this, and I don't know if there are any other switch models involved. The 45xx Supervisor 8 and the 3850 each have some wireless controller capability built in, too.– Ron Maupin ♦Commented Feb 12, 2016 at 8:16
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2@KorXo, I just found this: Cisco Catalyst Multigigabit Ethernet– Ron Maupin ♦Commented Feb 12, 2016 at 8:19
Wireless connectivity is a half-duplex medium. So while a single PC connected wirelessly at 150Mbps to the AP that is connected to the LAN at 100Mbps seems silly, the idea is that many PCs or hosts will be connected to the AP, sharing that 150Mbps half-duplex connection. The 100Mbps wired connection is probably full-duplex, so you are still getting better throughput on the wired side even if it is listed as 2/3rds the speed.
As an aside to KorXo's port-channel answer, port-channeling is a redundancy mechanism, not a speed improvement mechanism. The hashing algorithm of a port-channel typically only sends data down one of the links, not both. Even the best hashing algorithm (in my opinion) of src-dest-ip mixed with src-dest-port will only send each TCP/UDP connection down the same one link. Now a new connection to the same server will use a different source port, so might use the 2nd link, but you are still only using a 1Gb link for each connection. You get no better throughput because of that.
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1"You get no better throughput because of that." If you have only a handful of active users sure but if you have a load of active users (e.g. the access point in a conference hall) then you are going to end up with about half the traffic going down each port. So the average throughput will be improved by bonding (assuming it's not bottlenecked elsewhere). Commented Feb 12, 2016 at 20:21