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JohnInSJ
Premium
join:2003-09-22
Aptos, CA

1 recommendation

reply to johnnn

Re: [Speed] Congested Comcast Peering with Akamai, Google in Mid

said by johnnn:

various observations

But there is no way to verify your observations.

Let's start with some actual facts

- what tier are you on

- what is your home network like

- what load are you putting on your connection (are you uploading while attempting these downloads, for example? I don't care what you're uploading - just tell me if you're using x% of your uplink... do you have 1, 2, 5, 20 devices sharing the connection? Are any of THEM uploading, or downloading at the same time? Can you disconnect everything from the network except one test machine and try to reproduce the problem? Did you verify the machine being used to test is free of malware and rootkits?)

- what devices are you attempting to render HD content streams on, and are those devices themselves having performance issues

- what are your modem signals when you are having these issues?

Comcast has many millions of users. If they were having regular widespread CDN peering issues, we'd see millions of users complaining about it.

Your problem might be one of local congestion on your connection, or even a signal/drop issue. Jumping directly to a local node, neighborhood, or CDN peering congestion issue seems to be sidestepping much more likely problems
--
My place : »www.schettino.us

johnnn

join:2007-01-25
Ypsilanti, MI
Thanks, JohnInSJ, here goes:

-Blast (25/4)
-I have a Motorola SB 6121; 4 downstream, 3 upstream channels bonded.
-I have all cat5e cable between devices (modem-router, router-computers). The router is a TP-Link TL-WR2543ND with 4 gigabit ports.
-I am not loading the connection when I perform tests
-I have run tests with multiple computers hooked directly to the modem
-I have had two tech visits to verify good line quality (both found a very stable plant/no issues using their JDSU equipment)
-All of my computers are free of malware and experience little/no resource contention during testing. I have tested on Windows 7, Windows 8, Ubuntu 12.04.
-I have asked pointed questions about congestion in my area in Comcast Direct ("can you confirm there is congestion between endpoints in my area and certain peering/transit links?") and received nonspecific answers which refrain from disconfirming.


JohnInSJ
Premium
join:2003-09-22
Aptos, CA
I assume when the techs visited (as in when they were there testing your line/modem signals) you were NOT seeing the issue?

Comcast doesn't generally have congestion issues anywhere, in the modern era. This is is why I would think this is something other than congestion - if its intermittent, does it vary in time of day, day of week?
--
My place : »www.schettino.us


NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage

1 recommendation

reply to johnnn
I am not going to try to convince you that you are not seeing problems with some sites/services, but what you seem to expect Comcast to do is not going to happen for a residential or small business customer; they are only going to look at the results for the majority of similar customers.

The only way you are going to get any ISP to even bother to look at transit problems that are outside their network (especially if most of their other customers are not seeing/reporting the same problem) is if you are an Enterprise level customer (such as a customer with multiple Metro Ethernet or DS3 connections paying at least 5 digit amounts each month for service).

Sorry, but that is just the way that the industry works.
--
A well-regulated militia, being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed.

When governments fear people, there is liberty. When the people fear the government, there is tyranny.

johnnn

join:2007-01-25
Ypsilanti, MI
reply to JohnInSJ
Both visited during the day on weekdays. They didn't perform tests past basic speedtests to the Comcast server near Detroit. The throughput problem is definitely exacerbated during peak times. Recently it was so bad I couldn't stream a 360p YouTube video from beginning to end without pauses (in video info, stream fluctuates between 200-900kbps).

The reason I believe congestion (at some level) to be the issue is this: I could close the page, retry, get the same poor performance, but then run a shaperprobe and get 36mbps down (shaped to 25mbps after Powerboost tokens spent) from whichever servers host the Shaperprobe test files.

NetFixer, I agree with your assessment.


JohnInSJ
Premium
join:2003-09-22
Aptos, CA
said by johnnn:

Both visited during the day on weekdays. They didn't perform tests past basic speedtests to the Comcast server near Detroit. The throughput problem is definitely exacerbated during peak times. Recently it was so bad I couldn't stream a 360p YouTube video from beginning to end without pauses (in video info, stream fluctuates between 200-900kbps).

The reason I believe congestion (at some level) to be the issue is this: I could close the page, retry, get the same poor performance, but then run a shaperprobe and get 36mbps down (shaped to 25mbps after Powerboost tokens spent) from whichever servers host the Shaperprobe test files.

NetFixer, I agree with your assessment.

Are you using Comcast DNS or some other DNS? It's possible you're not getting content from the closest CDN connection point if you're using a non-comcast DNS.
--
My place : »www.schettino.us


depster

join:2001-06-07
united state
reply to johnnn
Is your router capable of IPv6? If so try disabling that capability. I have a netgear router that was in auto mode, and was in 6to4 tunnel mode. Caused my streaming of netflix and youtube to be terrible.

johnnn

join:2007-01-25
Ypsilanti, MI
reply to JohnInSJ
I'm using anycast (75.75.75.75), and my router doesn't support IPv6.


depster

join:2001-06-07
united state
It may be that your local router is being upgraded... in your first post Hop 3 indicated a 'te' interface.

When I just tracerouted to it now, it's showing as a 'xe' interface.
  3    20 ms    10 ms    10 ms  96.120.41.137
  4    12 ms     7 ms     7 ms  xe-8-2-0-sur01.grandrapids.mi.michigan.comcast.net [68.86.140.185]
  5    17 ms    19 ms    27 ms  te-0-2-0-4-ar01.taylor.mi.michigan.comcast.net [69.139.254.29]
  6    18 ms    17 ms    19 ms  xe-7-3-0-sur01.wannarbor.mi.michigan.comcast.net [68.85.218.201]
 


DrDrew
That others may surf
Premium
join:2009-01-28
SoCal
kudos:16
said by depster:

It may be that your local router is being upgraded... in your first post Hop 3 indicated a 'te' interface.

When I just tracerouted to it now, it's showing as a 'xe' interface.

  3    20 ms    10 ms    10 ms  96.120.41.137
  4    12 ms     7 ms     7 ms  xe-8-2-0-sur01.grandrapids.mi.michigan.comcast.net [68.86.140.185]
  5    17 ms    19 ms    27 ms  te-0-2-0-4-ar01.taylor.mi.michigan.comcast.net [69.139.254.29]
  6    18 ms    17 ms    19 ms  xe-7-3-0-sur01.wannarbor.mi.michigan.comcast.net [68.85.218.201]
 

It's a different interface of the same router. OP's being from the edge of the network inbound, yours being from the core of the network outbound.
--
Two is one, one is none. If it's important, back it up... Somethimes 99.999% availability isn't even good enough.

johnnn

join:2007-01-25
Ypsilanti, MI
DrDrew is right. When I do tracerts *to* the edge they travel through an xe interface.


JohnInSJ
Premium
join:2003-09-22
Aptos, CA
reply to johnnn
said by johnnn:

I'm using anycast (75.75.75.75), and my router doesn't support IPv6.

Try using comcast's DNS. Just for grins.
--
My place : »www.schettino.us


EG
The wings of love
Premium
join:2006-11-18
Union, NJ
kudos:10

1 edit

3 recommendations

reply to depster
FWIW, just a point. As Dr.Drew stated, it's the same physical router. This data needs to also be examined when evaluating the rDNS info on hops;

te-8-2-ur02
xe-7-0-sur01

Even though the IP address is the same, the slot, port, and ring data is different.

Some examples of some meanings;

Some examples;

ge = gigabit ethernet.

te / xe= ten gigabit ethernet.

p, po, pos = Packet Over Sonet (an OC-3 or faster connection).

XE / TE = Juniper / Cisco 10GigE Interface
be / ae = Cisco Bundle Ethernet / Juniper Aggregate Ethernet

he = hundred gigabit ethernet.

1-1, 1-2, 1-11, 6-1, 9-1, 2-2, etc. = slot and port.

ar01, cr01, ur01

User Ring (UR), Area Ring (AR), Core Ring (CR) routing.

johnnn

join:2007-01-25
Ypsilanti, MI
EG, you're the best.


EG
The wings of love
Premium
join:2006-11-18
Union, NJ
kudos:10
I doubt that but thanks for your kind words !


NathanO

join:2008-08-21
Moorestown, NJ
reply to JohnInSJ
That is Comcast's anycast DNS


whfsdude
Premium
join:2003-04-05
Washington, DC
Reviews:
·Comcast
reply to EG
said by EG:

User Ring (UR), Area Ring (AR), Core Ring (CR) routing.

The one I've never understood is "SUR." I have yet to see this interface name used outside of Comcast. Happen to know?

johnnn

join:2007-01-25
Ypsilanti, MI
Click for full size
New interface on the
Click for full size
KS route
Click for full size
CA route
Click for full size
Peak time comparison
There appear to be significant changes underway. One of the routers hostnames has reappeared, and I'm on a different interface. A hop prior to Pontiac has been eliminated from the previous configuration.

There was likely some sort of maintenance window on Friday morning as evidenced by the smokeping graphs attached (this makes sense, as it corresponds with the lowest utilization period for the college town I'm in). Comparing the ICMP performance for peak windows between this week and last, there's been a significant improvement.


JohnInSJ
Premium
join:2003-09-22
Aptos, CA
reply to NathanO
said by NathanO:

That is Comcast's anycast DNS

Perhaps using one from here »www.whatsmydns.net/dns/usa/comcast.html

Michigan

Primary DNS: 68.87.77.130

Secondary DNS: 68.87.72.130

Primary IPv6 DNS: 2001:558:1016:C:68:87:77:130

Secondary IPv6 DNS: 2001:558:100E:4:68:87:72:130

Would yield different CDN entry points?
--
My place : »www.schettino.us


ArrayList
netbus developer
Premium
join:2005-03-19
Brighton, MA
Reviews:
·RCN CABLE
·Comcast
reply to EG
said by EG:

ge = gigabit ethernet.

te / xe= ten gigabit ethernet.

p, po, pos = Packet Over Sonet (an OC-3 or faster connection).

XE / TE = Juniper / Cisco 10GigE Interface
be / ae = Cisco Bundle Ethernet / Juniper Aggregate Ethernet

he = hundred gigabit ethernet.

1-1, 1-2, 1-11, 6-1, 9-1, 2-2, etc. = slot and port.

ar01, cr01, ur01

User Ring (UR), Area Ring (AR), Core Ring (CR) routing.

holy cow man. Thanks for this information. I know it's pretty trivial for non-comcast network engineers, but it really helps add some light into where my packets go when they leave town.


depster

join:2001-06-07
united state
reply to whfsdude
said by whfsdude:

said by EG:

User Ring (UR), Area Ring (AR), Core Ring (CR) routing.

The one I've never understood is "SUR." I have yet to see this interface name used outside of Comcast. Happen to know?

Maybe Switched User Ring?


NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage
reply to JohnInSJ
said by JohnInSJ:

said by NathanO:

That is Comcast's anycast DNS

Perhaps using one from here »www.whatsmydns.net/dns/usa/comcast.html

...

Would yield different CDN entry points?

That is exactly what I do for the forwarding servers in my in-house DNS server. I chose the primary servers for Atlanta and Chicago because most of my routes go through either Atlanta or Chicago.





C:\>dig -x 68.87.68.162
 
; <<>> DiG 9.9.2 <<>> -x 68.87.68.162
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62426
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
 
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1280
;; QUESTION SECTION:
;162.68.87.68.in-addr.arpa.     IN      PTR
 
;; ANSWER SECTION:
162.68.87.68.in-addr.arpa. 1196 IN      PTR     nrcns.s3woodstock.ga.atlanta.comcast.net.
 
;; Query time: 31 msec
;; SERVER: 192.168.9.2#53(192.168.9.2)
;; WHEN: Sun Jan 27 13:11:54 2013
;; MSG SIZE  rcvd: 108
 
C:\>dig -x 68.87.72.130
 
; <<>> DiG 9.9.2 <<>> -x 68.87.72.130
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26004
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
 
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1280
;; QUESTION SECTION:
;130.72.87.68.in-addr.arpa.     IN      PTR
 
;; ANSWER SECTION:
130.72.87.68.in-addr.arpa. 6112 IN      PTR     nrcns.area4.il.chicago.comcast.net.
130.72.87.68.in-addr.arpa. 6112 IN      PTR     chic-cns.area4.il.chicago.comcast.net.
 
;; Query time: 15 msec
;; SERVER: 192.168.9.2#53(192.168.9.2)
;; WHEN: Sun Jan 27 13:12:24 2013
;; MSG SIZE  rcvd: 125
 



--
A well-regulated militia, being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed.

When governments fear people, there is liberty. When the people fear the government, there is tyranny.

makaze
Premium
join:2004-02-23
USA

1 recommendation

reply to depster
said by depster:

said by whfsdude:

said by EG:

User Ring (UR), Area Ring (AR), Core Ring (CR) routing.

The one I've never understood is "SUR." I have yet to see this interface name used outside of Comcast. Happen to know?

Maybe Switched User Ring?

Nah it's a Super UR. In most areas it's a juniper with multiple AR connections for redundancy.

johnnn

join:2007-01-25
Ypsilanti, MI
So based on the info in this thread, the changes in throughput (things are much improved), and the routing changes I've observed, it looks like Comcast hooked my neighborhood's CMTS (and likely all of wannarbor) into a Super UR whereas before it routed through two regular 10GigE URs on its way to the AR in Pontiac.