Cable Forum - View Single Post - 50M Think Broadband Ping Monitor Results (POST YOURS)

Sephiroth · 04-10-2013, 08:07

The BBC according to my eyes had an average of 20 ms. The max at the Hemel CMTS means that a packet addressed directly to VM's Hemel server had an RTT of 1472/1565. This means that occasionally, the low priority pings are given degraded priority over other traffic - but note, they are not discarded which is what they would be if the CMTS was congested.

The post-RS errors shouldn't be occurring. True, the rate is lowish but they are lost packets and will affect your experience. When you changed IP addresses, were the past and current address totally different? The usual thing if you switch off for a week or more is that you get a new IP address on the same line card and that your downstream channels are in the same bonding group. Have your downstream channel numbers changed? If the channels are totally different then you've been moved to a different line card and so has everyone else on your cabinet. If all that has changed, there has possibly been a resegmentation and the loading on your segment is different from before.

The Post-RS errors are not congruent with the SNR/RxMER values. I can't see if you have an SH2 or a SH1; the former always shows lower SNR values than the SH1. But either way, the reported SNR is more than adequate to support no noise, which is the usual cause for packet loss on the downstream. Also, the SH1 is known not to count post-RS errors correctly.

So, if the post-RS count is correct, that suggests the packets either arrive corrupted at the SH or are corrupted en-route which needs to be investigated by VM.

It might pay to see what your neighbours are experiencing.

04-10-2013, 08:07	#4046
Sephiroth Sulking in the Corner Join Date: Jul 2009 Location: RG41 Services: 1 Gbps; Hub 4 MM; ASUS RT-AX88U; Ultimate VOLT. BT Infinity2; Devolo 1200AV Posts: 11,955	Re: Think Broadband Ping Monitor Results (POST YOURS) The BBC according to my eyes had an average of 20 ms. The max at the Hemel CMTS means that a packet addressed directly to VM's Hemel server had an RTT of 1472/1565. This means that occasionally, the low priority pings are given degraded priority over other traffic - but note, they are not discarded which is what they would be if the CMTS was congested. The post-RS errors shouldn't be occurring. True, the rate is lowish but they are lost packets and will affect your experience. When you changed IP addresses, were the past and current address totally different? The usual thing if you switch off for a week or more is that you get a new IP address on the same line card and that your downstream channels are in the same bonding group. Have your downstream channel numbers changed? If the channels are totally different then you've been moved to a different line card and so has everyone else on your cabinet. If all that has changed, there has possibly been a resegmentation and the loading on your segment is different from before. The Post-RS errors are not congruent with the SNR/RxMER values. I can't see if you have an SH2 or a SH1; the former always shows lower SNR values than the SH1. But either way, the reported SNR is more than adequate to support no noise, which is the usual cause for packet loss on the downstream. Also, the SH1 is known not to count post-RS errors correctly. So, if the post-RS count is correct, that suggests the packets either arrive corrupted at the SH or are corrupted en-route which needs to be investigated by VM. It might pay to see what your neighbours are experiencing. __________________ *Seph.* My advice is at your risk.