Latency to S33 IP

  • 31 March 2024
  • 5 replies


When I run a constant ping from my router to the modem (, which is directly connected to the Arris S33v2, I see latency spikes at times.  I would expect to always see <2ms, but it spikes to 300-400ms.

Why would this be the case?  How can I confirm that the S33v2 is running at 2.5Gbps on the main ethernet interface?  My router shows 2.5Gbps on eth1 (interface connected to modem).

I also see these errors on the interface (eth1) connected to the S33v2 from my router:
     rx_long_length_errors: 132
     rx_errors: 132
     rx_length_errors: 132
     rx_queue_0_csum_err: 12
     rx_queue_1_csum_err: 7
     rx_queue_2_csum_err: 9
     rx_queue_3_csum_err: 9
What would be causing these?

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5 replies

Userlevel 5
Badge +41

Are you facing this latency issue even on direct connection without router, that is connecting device like computer or laptop to the modem ethernet port and monitoring connection.

Could you please help us with your current speed plan and the router model number to assist on this case further.


Router is an iKOOLCORE R2 x86 running OpenWrt 23.05.3 r23809-234f1a2efa.  So it’s essentially a computer running routing software on it.  Ping command is being ran locally from the router directly over the eth1 port, which is connected to the Arris S33v2 modem.

Standard Specification Compliant    DOCSIS 3.1
Hardware Version    V1.0
Software Version    TB01.03.001.11_051722_212.S3

Speed plan is 1G/50M.

Userlevel 5
Badge +41

I suggest you to connect the modem to computer or laptop directly through ethernet cable and let us know whether the latency issues persists.

Since you are experiencing the latency issue while connecting with router, I suggest you to contact router’s manufacturer for further assistance.



This is not an issue with the router. I did a loopback test with my router prior to installation (eth0 and eth1 connected with loopback cable, ran ICMP and iperf) and did not have these issues. It's either there is a problem with the modem or the processor hardware handling the management interface on the modem is insufficient to handle the small amount of ICMP traffic going over it.

If the only way to get action is to run a test with my laptop again, I will do it outside of when my family uses the Internet and provide the data back to you.

Userlevel 5
Badge +41

I advise you to connect your modem directly to your computer using an Ethernet cable and see whether the issue still exists.