Best routers out there ?

[madires]

How packets travel through various switches, routers , fiber optic, undersea , satellite is an unknown. That is where stuff may go out of order. So by the time it arrives somewhere the packet order is no longer guaranteed. It is up to information contained in the payload to make sure the entire message can be reconstructed and packets can be put back in order.

As you know, TCP is able to deal with lost packets and packets out of order (will slow down the session). But many protocols don't have those features and have to rely on a proper packet order. Those protocols aren't inferior than TCP, they are simply designed for different purposes. Carriers/telcos/ISPs try to minimize out-of-order packets as much as possible, and network elements are designed to keep the packet order for each connection/session. Otherwise it would break some protocols.

[gmb42]

Carriers/telcos/ISPs try to minimize out-of-order packets as much as possible, and network elements are designed to keep the packet order for each connection/session. Otherwise it would break some protocols.

I wish.  Verizon, in particular, seem to love to re-order UDP packets.  Maybe my customers are buying some cheapskate package from Verizon that doesn't have the "supply packets in the order they were transmitted" extra-cost option though.

[madires]

That's really bad! But it's not the lack of the "plus package", it's poor network engineering. I know of specific line/interface cards causing out-of-order packets (mostly buffer issues of an ASIC) but those are usually replaced by the vendor with the next revision with a fixed ASIC. One of the protocols suffering from out-of-order packets is VoIP, i.e. RTP for streaming voice. RTP has a sequence number to detect packet loss and order problems but the VoIP phone can't wait and has to simply ignore late packets, creating poor voice quality.

[David Hess]

Carriers/telcos/ISPs try to minimize out-of-order packets as much as possible, and network elements are designed to keep the packet order for each connection/session. Otherwise it would break some protocols.

I wish.  Verizon, in particular, seem to love to re-order UDP packets.  Maybe my customers are buying some cheapskate package from Verizon that doesn't have the "supply packets in the order they were transmitted" extra-cost option though.

I would not surprise me if that is deliberate to discourage competing services which rely on real time traffic.

[gmb42]

Carriers/telcos/ISPs try to minimize out-of-order packets as much as possible, and network elements are designed to keep the packet order for each connection/session. Otherwise it would break some protocols.

I wish.  Verizon, in particular, seem to love to re-order UDP packets.  Maybe my customers are buying some cheapskate package from Verizon that doesn't have the "supply packets in the order they were transmitted" extra-cost option though.

I would not surprise me if that is deliberate to discourage competing services which rely on real time traffic.

This is telemetry data, so not actually real time.  Still, the protocol spec has an app note that says not to use UDP because of out-of-order issues, but customers do it because they think it will be cheaper than the extra overhead of TCP (when they're paying per-byte).  Unfortunately the extra re-transmissions required to "recover" from UDP out-of-order issues negate any savings they may have had.

[helius]

Considering the future of the web protocols (HTTP/3) is over UDP, this may be seriously disadvantageous to users of some ISPs.