Hi All, adding a few more group emails to see if we can get help - ripe-list@ripe.net, and others. Please read the thread. We are having a major bandwidth issue coming from multiple places around the world to multiple ISPs in Portugal. This is not isolated to us. Feel free to reach out directly if you have questions. Any help here would be appreciated. ________________________________ From: Justin Cottrell <justin.cottrell@mirazon.com> Sent: Wednesday, September 30, 2026 10:39 AM To: Pajevic, Aleksandar (External) <apajevic.ext@libertyglobal.com>; Pandya, Akshay <AkshayPandya@WireCo.com>; Steven Van Steen <svansteen@libertyglobal.com>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com>; noc@vodafoneziggo.com <noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com <b2b.ops@vodafoneziggo.com>; Liberty Global Central Network Support <cns@libertyglobal.com>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com> Cc: Liberty Global Peering Team <peering@aorta.net>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com>; Baumgarten, Rick <RickBaumgarten@WireCo.com>; Ribeiro, Artur <ArturRibeiro@WireCo.com>; PaulBratcher <PaulBratcher@wireco.com> Subject: Re: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal HI All, we are really suffering from this issue. Since it happens from multiple exiting ISPs it's a weird one. To answer your question @Pajevic, Aleksandar (External)<mailto:apajevic.ext@libertyglobal.com> - we have full communication, but when we push the TCP session with a good bit of bandwidth, that's when we see the issue. So, it is a TCP issue transiting the path. Please check some of the docs I sent; we clearly show that. Can we all get on a meeting to discuss? I can show examples, etc and we all might be able to get to the bottom of it. This is not just us - it seems to be a global transit issue. Could you guys test as well from Netherlands/Portugal/US, etc? ________________________________ From: Pajevic, Aleksandar (External) <apajevic.ext@libertyglobal.com> Sent: Monday, September 28, 2026 3:48 AM To: Pandya, Akshay <AkshayPandya@WireCo.com>; Justin Cottrell <justin.cottrell@mirazon.com>; Steven Van Steen <svansteen@libertyglobal.com>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com>; noc@vodafoneziggo.com <noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com <b2b.ops@vodafoneziggo.com>; Liberty Global Central Network Support <cns@libertyglobal.com>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com> Cc: Liberty Global Peering Team <peering@aorta.net>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com>; Baumgarten, Rick <RickBaumgarten@WireCo.com>; Ribeiro, Artur <ArturRibeiro@WireCo.com>; PaulBratcher <PaulBratcher@wireco.com> Subject: RE: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal NkdkJdXPPEBannerStart External Sender - From: ("Pajevic, Aleksandar (External)" <apajevic.ext@libertyglobal.com>)<https://us1.proofpointessentials.com/email-details/?k=k1&payload=53616c7465645f5fa0e320db43e368368bb95712a3875aa4496663a6b8cc7d33ab511cfdafaea7f62c8137ee3d816307032f3d9fa7aed94324356d50b90da7f8da03903ec6edf54163a6c4c2df06db5f523b5f97873a1700299878916c24dc786092466086560c16ff9b4f9cd6d9317036dfabaab889efe1e52c6a6fc378bafe1f6ba26fa1c2fbf54d2d111b7b93e5750dbb50a41e336b5fe822e5d3f2e6ae16114d6136f2630f3ebb95dcacf3bd6080d971d1c455cdf99325614b9a664aa75ccdad001c5af9cee573729986c9c7f857edec3be460e2cdc92b2cfab03fb3423c8bdce2c0c0b78a0569f71a412ab4c618> This message came from outside your organization. Learn More<https://us1.proofpointessentials.com/email-details/?k=k1&payload=53616c7465645f5fa0e320db43e368368bb95712a3875aa4496663a6b8cc7d33ab511cfdafaea7f62c8137ee3d816307032f3d9fa7aed94324356d50b90da7f8da03903ec6edf54163a6c4c2df06db5f523b5f97873a1700299878916c24dc786092466086560c16ff9b4f9cd6d9317036dfabaab889efe1e52c6a6fc378bafe1f6ba26fa1c2fbf54d2d111b7b93e5750dbb50a41e336b5fe822e5d3f2e6ae16114d6136f2630f3ebb95dcacf3bd6080d971d1c455cdf99325614b9a664aa75ccdad001c5af9cee573729986c9c7f857edec3be460e2cdc92b2cfab03fb3423c8bdce2c0c0b78a0569f71a412ab4c618> NkdkJdXPPEBannerEnd Hello Akshay, This is not a network issue. There is no packet loss, and no latency. 11 3592 PL 0 45.86 58.68 46.27 212.181.69.148.rev.vodafone.pt [148.69.181.212] 14 3595 PL 0 45.47 55.19 46.33 static-142-236-117-93.thenetworkfactory.nl [93.117.236.142] This looks like an application issue to me. Capture packets in wireshark while doing huge transfers, and check for window sizes, TCP flags, unseen packets, doubled acknowledges and other indicators. Best regards, Aleksandar Pajevic From: Pandya, Akshay <AkshayPandya@WireCo.com> Sent: Wednesday 23 September 2026 21:19 To: Justin Cottrell <justin.cottrell@mirazon.com>; Pajevic, Aleksandar (External) <apajevic.ext@libertyglobal.com>; Van Steen, Steven <svansteen@libertyglobal.com>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com>; noc@vodafoneziggo.com; b2b.ops@vodafoneziggo.com; Liberty Global Central Network Support <cns@libertyglobal.com>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com> Cc: Liberty Global Peering Team <peering@aorta.net>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com>; Baumgarten, Rick <RickBaumgarten@WireCo.com>; Ribeiro, Artur <ArturRibeiro@WireCo.com>; Paul Bratcher <paulbratcher@WireCo.com> Subject: RE: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Hello, please find attached results of MTR with more than 1000 packets. note: packet size is 1000 bytes Source: 93.117.236.142 Dest: 148.69.181.212 And reverse. Thanks, Akshay Pandya From: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>> Sent: Wednesday, September 23, 2026 10:42 AM To: Pajevic, Aleksandar (External) <apajevic.ext@libertyglobal.com<mailto:apajevic.ext@libertyglobal.com>>; Pandya, Akshay <AkshayPandya@WireCo.com<mailto:AkshayPandya@WireCo.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Ribeiro, Artur <ArturRibeiro@WireCo.com<mailto:ArturRibeiro@WireCo.com>>; Paul Bratcher <paulbratcher@WireCo.com<mailto:paulbratcher@WireCo.com>> Subject: Re: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Also, by 1000 you mean the size of the packets right? Justin Cottrell Systems Engineer T: +1 502-240-0404<tel:+1%20502-240-0404> 1640 Lyndon Farm Ct, Suite 102 Louisville, KY 40223 [cid:image001.png@01DD4F2E.925AD860]<https://rscloud.mirazon.com/rs/a0zDE9uu7yEPzqw> [cid:image002.png@01DD4F2E.925AD860] ________________________________ From: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>> Sent: Wednesday, September 23, 2026 11:05 AM To: Pajevic, Aleksandar (External) <apajevic.ext@libertyglobal.com<mailto:apajevic.ext@libertyglobal.com>>; Pandya, Akshay <AkshayPandya@WireCo.com<mailto:AkshayPandya@WireCo.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com> <noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com> <b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Ribeiro, Artur <ArturRibeiro@WireCo.com<mailto:ArturRibeiro@WireCo.com>>; PaulBratcher <PaulBratcher@wireco.com<mailto:PaulBratcher@wireco.com>> Subject: Re: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Just to make sure we do the test correctly Source: 93.117.236.142 Dest: 148.69.181.212 And reverse. ________________________________ From: Pajevic, Aleksandar (External) <apajevic.ext@libertyglobal.com<mailto:apajevic.ext@libertyglobal.com>> Sent: Wednesday, September 23, 2026 10:56 AM To: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>>; Pandya, Akshay <AkshayPandya@WireCo.com<mailto:AkshayPandya@WireCo.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com> <noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com> <b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Ribeiro, Artur <ArturRibeiro@WireCo.com<mailto:ArturRibeiro@WireCo.com>>; PaulBratcher <PaulBratcher@wireco.com<mailto:PaulBratcher@wireco.com>> Subject: RE: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Hello Justin, Thank you. Please focus on 2 IPs, source and destination, both ways, and only paths that pass Liberty Global network. I cannot add any other ISP support. Maybe VodafoneZiggo colleagues can, since you are theirs customer. But first I would like to see MTRs, and from there we will know more. Best regards, Aleksandar Pajevic From: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>> Sent: Wednesday 23 September 2026 16:50 To: Pajevic, Aleksandar (External) <apajevic.ext@libertyglobal.com<mailto:apajevic.ext@libertyglobal.com>>; Pandya, Akshay <AkshayPandya@WireCo.com<mailto:AkshayPandya@WireCo.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Ribeiro, Artur <ArturRibeiro@WireCo.com<mailto:ArturRibeiro@WireCo.com>>; PaulBratcher <PaulBratcher@wireco.com<mailto:PaulBratcher@wireco.com>> Subject: Re: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Thank you very much for your reply. We will do a MTR with 1000 min and send results from those Ips. Also, if you know of other ISPs that we go through in the traces that are bad, could you please add their support on this email thread? This is a real issue for us, and would be for any international communication, not just our business. Justin Cottrell Systems Engineer T: +1 502-240-0404<tel:+1%20502-240-0404> 1640 Lyndon Farm Ct, Suite 102 Louisville, KY 40223 [cid:image001.png@01DD4F2E.925AD860]<https://rscloud.mirazon.com/rs/a0k_kdxs6mEmjCq> [cid:image002.png@01DD4F2E.925AD860] From: Pajevic, Aleksandar (External) <apajevic.ext@libertyglobal.com<mailto:apajevic.ext@libertyglobal.com>> Sent: Wednesday, September 23, 2026 6:32 AM To: Pandya, Akshay <AkshayPandya@WireCo.com<mailto:AkshayPandya@WireCo.com>>; Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com> <noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com> <b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Ribeiro, Artur <ArturRibeiro@WireCo.com<mailto:ArturRibeiro@WireCo.com>>; PaulBratcher <PaulBratcher@wireco.com<mailto:PaulBratcher@wireco.com>> Subject: RE: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Hello Akshay, all, There are many traces and most of them not related to our network. Packets do not pass Liberty Global network at all. I have found some that do pass Liberty Global network, and I would like to focus on one flow, from one source IP to one destination IP and the other way around. We peer with VodafoneZiggo and there is no congestion and no packet loss on that interface, and also no congestion and no packet loss on the interface to Vodafone AS1273 in Amsterdam. Marked below. Those MTR are not sufficient, only 1 packet sent, should be 1000 min and preferably larger packets. But on those 2 MTRs we can see there is no latency increase, < 50 ms is normal latency between the Netherlands and Portugal. 1 packet sent and receive on 148.69.181.212. Also please allow ICMP traffic on of server with IP 93.117.236.142, otherwise we do not know what is percentage of the packet loss on that IP. Target Name: static-142-236-117-93.thenetworkfactory.nl IP: 93.117.236.142 Date/Time: 9/17/2026 2:19:35 AM - 9/17/2026 2:29:35 AM Hop Sent PL% Min Max Avg Host Name / [IP] 1 2 0 2.00 3.74 2.87 221.181.69.148.rev.vodafone.pt [148.69.181.221] 2 1 0 3.55 3.55 3.55 252.4.30.213.rev.vodafone.pt [213.30.4.252] 3 1 0 3.95 3.95 3.95 141.231.108.93.rev.vodafone.pt [93.108.231.141] 4 1 0 4.46 4.46 4.46 104.41.30.213.rev.vodafone.pt [213.30.41.104] 5 1 0 31.09 31.09 31.09 ae9-xcr3.prp.cw.net [195.2.30.242] 6 1 0 34.45 34.45 34.45 ae29-xcr1.ltw.cw.net [195.2.28.89] 7 1 100 * * * edge1.ams.macarne.com [140.235.115.1] 8 1 0 42.50 42.50 42.50 cz-prg01a-ra4-ae-99-50.aorta.net [84.116.136.161] 9 1 100 * * * [-] 10 1 100 * * * [-] 11 1 100 * * * asd-rc0001-cr101-be60-2.core.as33915.net [213.51.64.5] 12 1 0 44.35 44.35 44.35 ah-tr0009-dr101-be2.core.as33915.net [213.51.7.187] ? 1 100 * * * static-142-236-117-93.thenetworkfactory.nl [93.117.236.142] Target Name: 212.181.69.148.rev.vodafone.pt IP: 148.69.181.212 Date/Time: 17-9-2026 03:39:26 - 17-9-2026 03:49:26 Hop Sent PL% Min Max Avg Host Name / [IP] 1 3 0 0.25 1.77 0.78 static-141-236-117-93.thenetworkfactory.nl [93.117.236.141] 2 1 0 6.06 6.06 6.06 10.125.167.185 [10.125.167.185] 3 1 100 * * * [-] 4 1 0 8.02 8.02 8.02 nl-ams14a-ri1-ae51-0.core.as9143.net [213.51.64.186] 5 1 0 9.59 9.59 9.59 be27-scr1.amq.cw.net [195.2.14.73] <<<<<<<<<<< Vodafone AS1273 in Amsterdam peer IP 6 1 0 15.05 15.05 15.05 ae34-xcr1.slo.cw.net [195.2.31.2] 7 1 0 40.36 40.36 40.36 ae29-ucr1.lis.cw.net [195.2.22.30] 8 1 0 40.71 40.71 40.71 vfportugal-gw.lis.cw.net [195.10.57.10] 9 1 0 45.17 45.17 45.17 146.231.108.93.rev.vodafone.pt [93.108.231.146] 10 1 0 46.06 46.06 46.06 253.4.30.213.rev.vodafone.pt [213.30.4.253] 11 1 0 49.87 49.87 49.87 212.181.69.148.rev.vodafone.pt [148.69.181.212] Best regards, Aleksandar Pajevic From: Pandya, Akshay <AkshayPandya@WireCo.com<mailto:AkshayPandya@WireCo.com>> Sent: Monday 21 September 2026 18:22 To: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Ribeiro, Artur <ArturRibeiro@WireCo.com<mailto:ArturRibeiro@WireCo.com>>; Paul Bratcher <paulbratcher@WireCo.com<mailto:paulbratcher@WireCo.com>> Subject: RE: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Hello, following up on this conversation. Any help to speed up investigation would be greatly appreciated. let us know if we need to collect any evidences. Akshay Pandya | Systems Engineer WireCo | Leawood AkshayPandya@wireco.com<mailto:AkshayPandya@wireco.com> 8700 State Line Road, Suite 200 Leawood, KS 66206 www.wireco.com<http://www.wireco.com/> Twitter<https://urldefense.proofpoint.com/v2/url?u=https-3A__twitter.com_wireco&d=DwMFAg&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=t9xvTC838AHH8omyXbUQ0--hSUCfN_Oab_YPf6t9yXU&m=SZkF9_aCmcGh-OPBldPGvg3FDZrIvTSe63IJiFKuNDU&s=Dwc6M15NAxz1djK7G4Ie3w6oe9AXWMnIc8xqDXavZq8&e=> | LinkedIn<https://www.linkedin.com/company/wireco-worldgroup/> | Facebook<https://www.facebook.com/WireCoWorldGroup> From: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>> Sent: Wednesday, September 16, 2026 11:31 PM To: Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Pandya, Akshay <AkshayPandya@WireCo.com<mailto:AkshayPandya@WireCo.com>>; Ribeiro, Artur <ArturRibeiro@WireCo.com<mailto:ArturRibeiro@WireCo.com>>; Paul Bratcher <paulbratcher@WireCo.com<mailto:paulbratcher@WireCo.com>> Subject: Re: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Hi Steven, first thank you very much for helping us. We are in a rough spot here because this is one of our Datacenter hubs for our company. The main path I have seen thats an issue is here - PTMA Vodafone ↓ 148.69.181.221 213.30.4.252 93.108.231.141 213.30.41.104 ↓ CW 195.2.30.242 195.2.28.89 ↓ Aorta / AS33915 84.116.136.161 213.51.64.5 213.51.7.187 ↓ Netherlands 93.117.236.142 Attached are a lot of traceroutes from Pingplotter and a report to help show whats going on. Justin Cottrell Systems Engineer T: +1 502-240-0404<tel:+1%20502-240-0404> 1640 Lyndon Farm Ct, Suite 102 Louisville, KY 40223 [cid:image001.png@01DD4F2E.925AD860]<https://rscloud.mirazon.com/rs/a0iog-K-ZPLMJzK> [cid:image003.png@01DD4F2E.925AD860][cid:image002.png@01DD4F2E.925AD860] ________________________________ From: Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>> Sent: Wednesday, September 16, 2026 11:40 AM To: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com> <noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com> <b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Pandya, Akshay <akshaypandya@wireco.com<mailto:akshaypandya@wireco.com>>; Ribeiro, Artur <arturribeiro@wireco.com<mailto:arturribeiro@wireco.com>>; PaulBratcher <PaulBratcher@wireco.com<mailto:PaulBratcher@wireco.com>> Subject: RE: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Hi, Can someone please run & share traceroutes and ideally long term (15+ minutes, large packets) MTR outputs between end points (both ways ideally) that are impacted so we can start narrowing this down? Also are the issues observed 24x7 or only during specific days and/or times? Thanks, --Steven. From: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>> Sent: Wednesday, 16 September 2026 16:57 To: Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Pandya, Akshay <akshaypandya@wireco.com<mailto:akshaypandya@wireco.com>>; Ribeiro, Artur <arturribeiro@wireco.com<mailto:arturribeiro@wireco.com>>; PaulBratcher <PaulBratcher@wireco.com<mailto:PaulBratcher@wireco.com>> Subject: Re: P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal On top of what I sent below - this is an easy breakdown of where issues are and why we are reaching out Path Throughput Result 🇵🇹 PTMA (193.126.229.227) → Oliveira (83.240.185.210) 501 Mbps ✅ GOOD 🇵🇹 Oliveira (83.240.185.210) → PTMA (193.126.229.227) 484 Mbps ✅ GOOD 🇳🇱 Netherlands / NLSN (93.117.236.142) → PTMA Vodafone/NOS (148.69.181.212) 167 Mbps 🟡 DEGRADED 🇵🇹 PTMA Vodafone/NOS (148.69.181.212) → Netherlands / NLSN (93.117.236.142) 4.35 Mbps 🔴 SEVERE ISSUE 🇳🇱 Netherlands / NLSN (93.117.236.142) → PTMA (193.126.229.227) 346 Mbps ✅ GENERALLY GOOD 🇵🇹 PTMA (193.126.229.227) → Netherlands / NLSN (93.117.236.142) 42 Mbps 🔴 SEVERE ISSUE 🇳🇱 Netherlands / NLSN (93.117.236.142) → Oliveira (83.240.185.210) 186 Mbps 🟡 DEGRADED 🇵🇹 Oliveira (83.240.185.210) → Netherlands / NLSN (93.117.236.142) 31 Mbps 🔴 SEVERE ISSUE 🇵🇱 Poland / PLWL (95.171.126.204) → Oliveira (83.240.185.210) 113 Mbps 🟡 DEGRADED 🇵🇹 Oliveira (83.240.185.210) → Poland / PLWL (95.171.126.204) 78 Mbps 🔴 ISSUE 🇵🇹 PTMA → Poland VPN (10.110.x.x) ~65–90 Mbps class 🔴 ISSUE 🇳🇱 Netherlands (93.117.236.142) ↔ Poland (95.171.126.204) ~200–300 Mbps* ✅ NO SEVERE ISSUE SEEN 🇩🇪 Germany (212.89.130.163) → Netherlands (93.117.236.142) ~564 Mbps P8 ✅ GOOD / CONTROL We are seeing this same issue on multiple carriers. Thats why we are looking at the ISPs in between. Justin Cottrell Systems Engineer T: +1 502-240-0404<tel:+1%20502-240-0404> 1640 Lyndon Farm Ct, Suite 102 Louisville, KY 40223 [cid:image001.png@01DD4F2E.925AD860]<https://rscloud.mirazon.com/rs/a089nSJAdbm4LJe> [cid:image004.png@01DD4F2E.925AD860][cid:image002.png@01DD4F2E.925AD860] From: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>> Sent: Wednesday, September 16, 2026 9:43 AM To: Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com> <noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com> <b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Pandya, Akshay <akshaypandya@wireco.com<mailto:akshaypandya@wireco.com>>; Ribeiro, Artur <arturribeiro@wireco.com<mailto:arturribeiro@wireco.com>> Subject: Re: P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Here are my notes: We are investigating a repeatable TCP performance issue affecting communications between our sites in Portugal and multiple international locations. The most severe symptom is reduced TCP throughput when traffic is transmitted FROM Portugal toward international destinations. Testing has been performed from two separate Portugal locations, PTMA and Oliveira, using multiple remote destinations and multiple test methodologies. The most important control test is communication between the two Portugal locations. PTMA and Oliveira can sustain approximately 480–500 Mbps using a SINGLE TCP connection when communicating with each other. When essentially the same testing is performed from Portugal toward international destinations, individual TCP flows can fall to approximately 30–80 Mbps. Multiple parallel TCP streams frequently recover several hundred Mbps of aggregate throughput. This strongly suggests that the affected circuits have substantially more aggregate capacity than an individual affected TCP flow is able to utilize. AS33915 appears in routing associated with our Netherlands location and is therefore one of the networks we are asking to assist with investigation. We are not asserting that AS33915 is responsible for the condition. We are requesting assistance determining whether the impairment occurs within AS33915, at an interconnection/peering boundary, or elsewhere along the international path. ________________________________ 1. Primary Sites PTMA – Portugal Public test endpoint: 193.126.229.227 PTMA has been tested using two independent Internet connections. Testing has also been performed with the customer firewall and switching infrastructure removed from the path by connecting the test endpoint directly to the ISP circuit. Oliveira – Portugal Public test endpoint: 83.240.185.210 Oliveira is a physically separate Portugal location and provides an important independent comparison with PTMA. Netherlands Public test endpoint: 93.117.236.142 Routing associated with this destination traverses/reaches AS33915. Poland Public test endpoint: 95.171.126.204 Additional private/VPN testing has also been performed against the Poland network. ________________________________ 2. Critical Control Test – Portugal to Portugal The most useful baseline is PTMA ↔ Oliveira. These sites are independent Portugal locations. Single TCP PTMA → Oliveira: ~501 Mbps Oliveira → PTMA: ~484 Mbps Parallel TCP PTMA → Oliveira, 8 streams: ~505 Mbps Oliveira → PTMA, 8 streams: ~482 Mbps Significance There is essentially no severe single-flow TCP penalty between the Portugal sites. A single TCP connection is capable of utilizing approximately 500 Mbps. This is important because it demonstrates that neither Portugal endpoint has an inherent 30–80 Mbps TCP limitation. It also provides a known-good baseline against which the international tests can be compared. ________________________________ 3. PTMA ↔ Netherlands This has produced some of the clearest directional results. Single TCP Netherlands → PTMA: ~346 Mbps PTMA → Netherlands: ~42.2 Mbps This represents approximately an 8:1 difference between directions during the comparable test. Eight Parallel TCP Streams Netherlands → PTMA: ~909 Mbps PTMA → Netherlands: ~292 Mbps The ability to reach approximately 292 Mbps outbound using parallel connections while a single connection reaches only approximately 42 Mbps demonstrates that substantially more aggregate path capacity exists than the single TCP connection can utilize. UDP Additional public-path UDP testing delivered approximately: 300 Mbps offered → ~300 Mbps delivered 400 Mbps offered → ~401 Mbps delivered A 500 Mbps offered-load test averaged approximately 384 Mbps and exhibited significant short-term throughput variation. Again, the path can transport substantially more traffic than the affected ~42 Mbps single TCP flow. Latency PTMA ↔ Netherlands RTT is approximately: 46 ms TCP PsPing testing was stable and did not show persistent end-to-end loss during the referenced test. ________________________________ 4. Oliveira → Netherlands A second Portugal site reproduces the same general behavior. Single TCP Oliveira → Netherlands: ~31 Mbps Eight Parallel TCP Streams Oliveira → Netherlands: ~466 Mbps This is a particularly significant result. The same Oliveira endpoint that sustains approximately 484 Mbps using ONE TCP connection to PTMA sustains only approximately 31 Mbps on a single TCP connection toward the Netherlands. Adding parallel connections increases aggregate throughput to approximately 466 Mbps. Therefore: Oliveira → PTMA: ~484 Mbps single TCP Oliveira → Netherlands: ~31 Mbps single TCP Oliveira → Netherlands: ~466 Mbps with 8 TCP streams This is difficult to reconcile with a simple bandwidth limitation at the Oliveira site. ________________________________ 5. Oliveira → Poland The issue is not limited to the Netherlands test. Testing from Oliveira toward Poland also demonstrated reduced outbound TCP performance. Single TCP Oliveira → Poland: ~78 Mbps Eight Parallel TCP Streams Oliveira → Poland: ~143 Mbps Although the characteristics are not identical to the Netherlands path, international outbound performance is again significantly below the approximately 480–500 Mbps single-flow performance demonstrated between the two Portugal sites. ________________________________ 6. PTMA → Poland Private/VPN testing has also demonstrated outbound degradation from PTMA toward Poland. One eight-stream PTMA → Poland test achieved approximately: ~90 Mbps aggregate UDP testing at lower offered rates performed substantially better from a packet-loss perspective. These tests involve VPN/private infrastructure and are therefore treated as supporting evidence rather than our primary public-Internet control. Our strongest evidence remains the direct public endpoint testing. ________________________________ 7. Additional Geographic Testing Testing has also been performed from Germany and the United States. Germany testing demonstrated that our Netherlands endpoint is capable of receiving substantially higher aggregate TCP throughput from another geographic region. For example, Germany → Netherlands using eight TCP streams with a 1 MB window reached approximately: ~564 Mbps The same Netherlands endpoint therefore is not simply capped at the low throughput observed from Portugal. United States/private-path testing has also been performed, although because those tests include VPN infrastructure we do not use them as the primary evidence for this escalation. The public Portugal ↔ Netherlands and Portugal ↔ Portugal comparisons provide a much cleaner control. ________________________________ 8. PTMA Direct-to-ISP Testing A significant amount of effort has been made to eliminate customer equipment as a cause. At PTMA, testing has been performed with the test computer connected directly to the ISP service. This removes the following equipment/functions from the tested path: * FortiGate firewall * IPsec VPN * UTM/security inspection * Cisco access switching * Customer LAN infrastructure The international behavior remained reproducible. Testing was subsequently performed through a SECOND independent PTMA Internet provider. The two PTMA providers use materially different upstream transit paths. Despite this, similar destination-dependent and flow-dependent performance behavior was observed. This significantly reduces the likelihood that a single PTMA firewall, switch, ISP access circuit, or unique upstream carrier is responsible for the entire issue. ________________________________ 9. Flow-Count Dependency One of the most repeatable characteristics is the difference between single and parallel TCP flows. Examples: PTMA → Netherlands: Single TCP: ~42 Mbps 8 TCP streams: ~292 Mbps Oliveira → Netherlands: Single TCP: ~31 Mbps 8 TCP streams: ~466 Mbps PTMA → Oliveira: Single TCP: ~501 Mbps 8 TCP streams: ~505 Mbps The Portugal domestic path behaves normally. The international paths exhibit dramatically greater dependence on parallel TCP flows. This suggests investigation should focus on conditions capable of disproportionately affecting individual long-lived TCP flows rather than solely aggregate interface utilization. Potential areas for investigation include, but are not limited to: * Low-level packet loss * TCP retransmissions * Queue congestion * Microbursts * Policers * Traffic shaping * ECMP/flow hashing * Congested individual LAG/ECMP members * Peering/interconnection congestion * Asymmetric routing * Receive-window/congestion-window interaction * Packet reordering * Path-specific MTU/MSS behavior These are investigation areas, not conclusions regarding the root cause. ________________________________ 10. Routing / AS33915 Observation During testing toward the Netherlands endpoint, routing associated with the destination enters or converges toward the AS33915 network. Observed AS33915-associated addresses on tested paths have included: 213.51.64.x 213.51.7.187 Earlier testing from PTMA's primary ISP reached the Netherlands through an AS6453 path before entering the Netherlands-side network. Testing through PTMA's second provider followed a materially different Vodafone/Cable & Wireless transit path. Despite the different upstream paths from Portugal, similar performance behavior was observed toward the Netherlands destination. This makes the common downstream portion of the path particularly interesting. However, we want to emphasize: We are NOT concluding that AS33915 is responsible. The problem could exist: * within an upstream transit network, * at the interconnection with AS33915, * within AS33915, * on the destination access network, * or as the result of an interaction between multiple networks. We are requesting AS33915's assistance specifically because visibility from within the network is required to distinguish these possibilities. ________________________________ 11. What We Would Like AS33915 to Investigate We would appreciate review of the path toward: 93.117.236.142 during synchronized testing from our Portugal endpoints. Specifically, we would appreciate examination of: 1. Interface utilization and congestion along the relevant path. 1. Interface discards or queue drops. 1. LAG/ECMP member utilization and errors. 1. Whether individual TCP flows could be consistently hashing onto a congested or impaired member. 1. Policers or traffic-management policies affecting traffic from the relevant Portugal prefixes. 1. Peering/interconnection utilization toward the Portugal transit providers. 1. BGP path selection for traffic toward and from: * 193.126.229.227 * 83.240.185.210 1. Return-path routing from AS33915 toward both Portugal destinations. 1. Any asymmetric routing between the forward and reverse paths. 1. Packet loss that may be too small to appear clearly in ordinary ICMP testing but significant enough to affect long-RTT TCP throughput. 1. Any known congestion or capacity issue at the relevant European interconnection points. ________________________________ 12. Proposed Coordinated Test We would be happy to coordinate a live test with the AS33915 network team. The preferred test would use: Portugal: 193.126.229.227 Netherlands: 93.117.236.142 We can run the following sequence while AS33915 monitors the relevant interfaces: 1. Single TCP stream – Portugal → Netherlands 1. Single TCP stream – Netherlands → Portugal 1. Eight TCP streams – Portugal → Netherlands 1. Eight TCP streams – Netherlands → Portugal 1. Controlled UDP at 100 Mbps 1. Controlled UDP at 200 Mbps 1. Controlled UDP at 300 Mbps 1. Traceroute/MTR in both directions We can provide exact timestamps to correlate each test with network telemetry. Packet captures can also be collected simultaneously at both endpoints if required. ________________________________ 13. Summary of Key Evidence The core issue can be summarized very simply: PTMA → Oliveira, Portugal: ~501 Mbps SINGLE TCP Oliveira → PTMA, Portugal: ~484 Mbps SINGLE TCP PTMA → Netherlands: ~42 Mbps SINGLE TCP Oliveira → Netherlands: ~31 Mbps SINGLE TCP Yet parallel connections can recover hundreds of Mbps on the affected international paths. This means the Portugal systems are demonstrably capable of approximately 500 Mbps single-flow TCP performance. The severe degradation emerges primarily when traffic traverses longer/international paths. The condition has been reproduced: * From two separate Portugal sites * Through multiple Portugal Internet providers * With customer firewall/switch infrastructure removed in direct testing * Using public Internet endpoints * In both single and parallel TCP testing * With UDP demonstrating additional aggregate path capacity We therefore believe this warrants investigation at the IP transit/peering/core-network level. Again, we are not assigning fault to AS33915. We are asking for assistance determining whether the impairment occurs inside AS33915, at an interconnection involving AS33915, or elsewhere along the path. We can provide raw iPerf3 results, PsPing output, traceroutes, PathPing output, source/destination addresses, packet captures and exact timestamps. Thank you for any assistance in getting this case to the appropriate IP Core / Backbone / Peering engineering team. From: Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>> Sent: Wednesday, September 16, 2026 9:40 AM To: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com> <noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com> <b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>>; LibertyGlobal-DL- CoreNetworkOperations <CoreNetworkOperations@libertyglobal.com<mailto:CoreNetworkOperations@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Pandya, Akshay <akshaypandya@wireco.com<mailto:akshaypandya@wireco.com>>; Ribeiro, Artur <arturribeiro@wireco.com<mailto:arturribeiro@wireco.com>> Subject: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Hi CNS L3, Kindly check the email trail, investigate the issue, and share your findings at the earliest. Thanks & Regards, Sachin Jadhav L1 Noc Engineer – CSD IP and Optical Infrastructure Hi CNS L3, Kindly check the email trail, investigate the issue, and share your findings at the earliest. Thanks & Regards, Sachin Jadhav L1 Noc Engineer – CSD IP and Optical Infrastructure Email : CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com> CSDOpticalInfrastructure@libertyglobal.com<mailto:CSDOpticalInfrastructure@libertyglobal.com> [cid:image010.png@01DD4F2E.925AD860]+31207783444 – Option 2 , 3 or 4 (+31207788129 - backup) [cid:image011.png@01DD4F2E.925AD860][cid:image012.png@01DD4F2E.925AD860] From: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>> Sent: Wednesday 16 September 2026 15:33 To: Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>>; Baumgarten, Rick <RickBaumgarten@WireCo.com<mailto:RickBaumgarten@WireCo.com>>; Pandya, Akshay <akshaypandya@wireco.com<mailto:akshaypandya@wireco.com>>; Ribeiro, Artur <arturribeiro@wireco.com<mailto:arturribeiro@wireco.com>> Subject: Re: P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Adding a few people for Wireco - the client having issues. We are a vodafone customer both in Netherlands and Portugal. Let me know what our next steps are. I am happy to send over any needed info. Justin Cottrell Systems Engineer T: +1 502-240-0404<tel:+1%20502-240-0404> 1640 Lyndon Farm Ct, Suite 102 Louisville, KY 40223 [cid:image001.png@01DD4F2E.925AD860]<https://rscloud.mirazon.com/rs/a0dGLgnwf8S3t6t> [cid:image004.png@01DD4F2E.925AD860][cid:image002.png@01DD4F2E.925AD860] From: Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>> Sent: Wednesday, September 16, 2026 2:29 AM To: Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>>; Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com> <noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com> <b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>>; Liberty Global Central Network Support <cns@libertyglobal.com<mailto:cns@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; Liberty Global-Mail2Ticket Update <mail2ticketupdate@libertyglobal.com<mailto:mail2ticketupdate@libertyglobal.com>> Subject: [External] P4|INC000005996181|Bandwidth/Path issues from multiple providers to Portugal Hello CNS, We have raised incident INC000005996181 and assigned it to your queue for the mentioned issue. Kindly check and take the necessary action. Thanks & Regards, Omkar Zungare L1 Noc Engineer – CSD IP and Optical Infrastructure Hello CNS, We have raised incident INC000005996181 and assigned it to your queue for the mentioned issue. Kindly check and take the necessary action. Thanks & Regards, Omkar Zungare L1 Noc Engineer – CSD IP and Optical Infrastructure Email : CSDIPinfrastructureandVoice@libertyglobal.com<mailto:CSDIPinfrastructureandVoice@libertyglobal.com> CSDOpticalinfrastructure@libertyglobal.com<mailto:CSDOpticalinfrastructure@libertyglobal.com> [cid:image010.png@01DD4F2E.925AD860]+31207783444 – Option 2 , 3 or 4 (+31207788129 - backup) [cid:image011.png@01DD4F2E.925AD860] [cid:image012.png@01DD4F2E.925AD860] From: Van Steen, Steven <svansteen@libertyglobal.com<mailto:svansteen@libertyglobal.com>> Sent: Wednesday 16 September 2026 07:43 To: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>>; noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>; Liberty Global - CSD IP Infrastructure and Voice <CSDIPInfrastructureandVoice@libertyglobal.com<mailto:CSDIPInfrastructureandVoice@libertyglobal.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>> Subject: Re: Bandwidth/Path issues from multiple providers to Portugal Hi +CSD; please raise P5 for CNS to support Justin and Ziggo in investigating. We'll need some long term MTR both ways to start. Regards, —Steven ________________________________ From: Justin Cottrell <justin.cottrell@mirazon.com<mailto:justin.cottrell@mirazon.com>> Sent: Wednesday, September 16, 2026 5:34 AM To: noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com> <noc@vodafoneziggo.com<mailto:noc@vodafoneziggo.com>>; b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com> <b2b.ops@vodafoneziggo.com<mailto:b2b.ops@vodafoneziggo.com>> Cc: Liberty Global Peering Team <peering@aorta.net<mailto:peering@aorta.net>>; ripe-mnt@vodafoneziggo.com<mailto:ripe-mnt@vodafoneziggo.com> <ripe-mnt@vodafoneziggo.com<mailto:ripe-mnt@vodafoneziggo.com>> Subject: Bandwidth/Path issues from multiple providers to Portugal Hi — I’m trying to reach someone on the IP/core network side regarding an unusual international TCP performance issue involving traffic toward the VodafoneZiggo/AS33915 network. We have been troubleshooting this extensively with our ISPs and have direct iPerf, PsPing, traceroute and path data from multiple European locations. The interesting finding is that our Portugal sites can sustain approximately 480–500 Mbps on a single TCP flow when communicating within Portugal, but international single-flow TCP performance drops dramatically. For example, Oliveira, Portugal → Netherlands drops to approximately 31 Mbps on a single TCP flow, while 8 parallel flows over the same path can reach approximately 466 Mbps. We have also reproduced related behavior from two separate Portugal locations/providers, and earlier traces toward our Netherlands endpoint (93.117.236.142) converge at/near AS33915. I am not assuming AS33915 is the cause, but I am trying to find someone who could help review the relevant peering/core path or point us toward the correct NOC/network engineering team. I can provide exact timestamps, source/destination IPs, traceroutes and complete iPerf results if helpful. Please let me know what I can do to keep our troubleshooting going. Justin Cottrell Systems Engineer T: +1 502-240-0404<tel:+1%20502-240-0404> 1640 Lyndon Farm Ct, Suite 102 Louisville, KY 40223 [cid:image001.png@01DD4F2E.925AD860]<https://rscloud.mirazon.com/rs/a0sPqZaTJPGFfoa> [cid:image002.png@01DD4F2E.925AD860] [cid:image013.gif@01DD4F2E.925AD860]<https://www.mirazon.com/event/introduction-to-ai/> ________________________________ This email has been scanned for spam and viruses by Proofpoint Essentials. 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