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Discussion Groups | Rabbit-Semi | Duplicate Acks
This is a group for folks designing and programming embedded systems using the Rabbit Semiconductor C-programmable microcontroller. Rabbit Semi is a spin-off from Z-World who makes a variety of embedded modules and tools. This group is not affiliated with either Rabbit or Z-World, but is a user forum for sharing ideas, asking questions, flaunting knowledge, and other typical user group stuff. The Rabbit is a powerful uC, supported by a full-featured C-compiler.
Duplicate Acks - Steve Trigero - Jun 17 16:49:34 2008
When communicating via ethernet with an RCM3000, Wireshark reports duplicate ACKs
from the rabbit. Is this normal, a bug in the DC library, or maybe something I'm doing in
my application. How does one go about troubleshooting this?
Steve
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
from the rabbit. Is this normal, a bug in the DC library, or maybe something I'm doing in
my application. How does one go about troubleshooting this?
Steve
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
Re: Duplicate Acks - Bill_CT - Jun 18 12:28:31 2008
--- In r...@yahoogroups.com, Steve Trigero wrote:
>
> When communicating via ethernet with an RCM3000, Wireshark reports
duplicate ACKs
> from the rabbit. Is this normal, a bug in the DC library, or maybe
something I'm doing in
> my application. How does one go about troubleshooting this?
It's probably normal if it's the Rabbit sending them. It's one way to
change the TCP window size to avoid congestion. This is likely
happening because the Rabbit is slow and can't keep up at full link
speed with a PC (which can run full speed). You should see the window
size shrink and the dup acks become less frequent.
If it's the PC sending them, I'm surprised.
Be aware that WireShark can affect the bandwidth of the link it's
"watching". Though at the speeds you're working with it's not likely
to occur.
Bill
------------------------------------
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
>
> When communicating via ethernet with an RCM3000, Wireshark reports
duplicate ACKs
> from the rabbit. Is this normal, a bug in the DC library, or maybe
something I'm doing in
> my application. How does one go about troubleshooting this?
It's probably normal if it's the Rabbit sending them. It's one way to
change the TCP window size to avoid congestion. This is likely
happening because the Rabbit is slow and can't keep up at full link
speed with a PC (which can run full speed). You should see the window
size shrink and the dup acks become less frequent.
If it's the PC sending them, I'm surprised.
Be aware that WireShark can affect the bandwidth of the link it's
"watching". Though at the speeds you're working with it's not likely
to occur.
Bill
------------------------------------
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
Re: Re: Duplicate Acks - Steve Trigero - Jun 18 13:25:07 2008
The duplicate ACKs are from the Rabbit. What is the "TCP window size"
you mention?
Steve
----- Original Message ----
From: Bill_CT
To: r...@yahoogroups.com
Sent: Wednesday, June 18, 2008 9:28:20 AM
Subject: [rabbit-semi] Re: Duplicate Acks
--- In rabbit-semi@ yahoogroups. com, Steve Trigero wrote:
>
> When communicating via ethernet with an RCM3000, Wireshark reports
duplicate ACKs
> from the rabbit. Is this normal, a bug in the DC library, or maybe
something I'm doing in
> my application. How does one go about troubleshooting this?
It's probably normal if it's the Rabbit sending them. It's one way to
change the TCP window size to avoid congestion. This is likely
happening because the Rabbit is slow and can't keep up at full link
speed with a PC (which can run full speed). You should see the window
size shrink and the dup acks become less frequent.
If it's the PC sending them, I'm surprised.
Be aware that WireShark can affect the bandwidth of the link it's
"watching". Though at the speeds you're working with it's not likely
to occur.
Bill
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
you mention?
Steve
----- Original Message ----
From: Bill_CT
To: r...@yahoogroups.com
Sent: Wednesday, June 18, 2008 9:28:20 AM
Subject: [rabbit-semi] Re: Duplicate Acks
--- In rabbit-semi@ yahoogroups. com, Steve Trigero
>
> When communicating via ethernet with an RCM3000, Wireshark reports
duplicate ACKs
> from the rabbit. Is this normal, a bug in the DC library, or maybe
something I'm doing in
> my application. How does one go about troubleshooting this?
It's probably normal if it's the Rabbit sending them. It's one way to
change the TCP window size to avoid congestion. This is likely
happening because the Rabbit is slow and can't keep up at full link
speed with a PC (which can run full speed). You should see the window
size shrink and the dup acks become less frequent.
If it's the PC sending them, I'm surprised.
Be aware that WireShark can affect the bandwidth of the link it's
"watching". Though at the speeds you're working with it's not likely
to occur.
Bill
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
Re: Duplicate Acks - Bill_CT - Jun 18 16:38:19 2008
Google TCP window size
Bill
--- In r...@yahoogroups.com, Steve Trigero wrote:
>
> The duplicate ACKs are from the Rabbit. What is the "TCP window size"
> you mention?
>
> Steve
> ----- Original Message ----
> From: Bill_CT
> To: r...@yahoogroups.com
> Sent: Wednesday, June 18, 2008 9:28:20 AM
> Subject: [rabbit-semi] Re: Duplicate Acks
> --- In rabbit-semi@ yahoogroups. com, Steve Trigero
> >
> > When communicating via ethernet with an RCM3000, Wireshark reports
> duplicate ACKs
> > from the rabbit. Is this normal, a bug in the DC library, or maybe
> something I'm doing in
> > my application. How does one go about troubleshooting this?
>
> It's probably normal if it's the Rabbit sending them. It's one way to
> change the TCP window size to avoid congestion. This is likely
> happening because the Rabbit is slow and can't keep up at full link
> speed with a PC (which can run full speed). You should see the window
> size shrink and the dup acks become less frequent.
>
> If it's the PC sending them, I'm surprised.
>
> Be aware that WireShark can affect the bandwidth of the link it's
> "watching". Though at the speeds you're working with it's not likely
> to occur.
>
> Bill
>
------------------------------------
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
Bill
--- In r...@yahoogroups.com, Steve Trigero
>
> The duplicate ACKs are from the Rabbit. What is the "TCP window size"
> you mention?
>
> Steve
> ----- Original Message ----
> From: Bill_CT
> To: r...@yahoogroups.com
> Sent: Wednesday, June 18, 2008 9:28:20 AM
> Subject: [rabbit-semi] Re: Duplicate Acks
> --- In rabbit-semi@ yahoogroups. com, Steve Trigero
> >
> > When communicating via ethernet with an RCM3000, Wireshark reports
> duplicate ACKs
> > from the rabbit. Is this normal, a bug in the DC library, or maybe
> something I'm doing in
> > my application. How does one go about troubleshooting this?
>
> It's probably normal if it's the Rabbit sending them. It's one way to
> change the TCP window size to avoid congestion. This is likely
> happening because the Rabbit is slow and can't keep up at full link
> speed with a PC (which can run full speed). You should see the window
> size shrink and the dup acks become less frequent.
>
> If it's the PC sending them, I'm surprised.
>
> Be aware that WireShark can affect the bandwidth of the link it's
> "watching". Though at the speeds you're working with it's not likely
> to occur.
>
> Bill
>
------------------------------------
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
Re: Re: Duplicate Acks - Steve Trigero - Jun 18 17:42:59 2008
The tcp Tx and Rx buffer sizes in the rabbit are 512 bytes. The amount of data the
rabbit receives in any one message is less that 32-bytes. I don't see how "TCP Window
size" would be a factor. But neither can I explain why the rabbit would send multiple
acks for a message.
Still looking for clues.
----- Original Message ----
From: Bill_CT
To: r...@yahoogroups.com
Sent: Wednesday, June 18, 2008 1:38:11 PM
Subject: [rabbit-semi] Re: Duplicate Acks
Google TCP window size
Bill
--- In rabbit-semi@ yahoogroups. com, Steve Trigero wrote:
>
> The duplicate ACKs are from the Rabbit. What is the "TCP window size"
> you mention?
>
> Steve
> ----- Original Message ----
> From: Bill_CT
> To: rabbit-semi@ yahoogroups. com
> Sent: Wednesday, June 18, 2008 9:28:20 AM
> Subject: [rabbit-semi] Re: Duplicate Acks
> --- In rabbit-semi@ yahoogroups. com, Steve Trigero
> >
> > When communicating via ethernet with an RCM3000, Wireshark reports
> duplicate ACKs
> > from the rabbit. Is this normal, a bug in the DC library, or maybe
> something I'm doing in
> > my application. How does one go about troubleshooting this?
>
> It's probably normal if it's the Rabbit sending them. It's one way to
> change the TCP window size to avoid congestion. This is likely
> happening because the Rabbit is slow and can't keep up at full link
> speed with a PC (which can run full speed). You should see the window
> size shrink and the dup acks become less frequent.
>
> If it's the PC sending them, I'm surprised.
>
> Be aware that WireShark can affect the bandwidth of the link it's
> "watching". Though at the speeds you're working with it's not likely
> to occur.
>
> Bill
>
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
rabbit receives in any one message is less that 32-bytes. I don't see how "TCP Window
size" would be a factor. But neither can I explain why the rabbit would send multiple
acks for a message.
Still looking for clues.
----- Original Message ----
From: Bill_CT
To: r...@yahoogroups.com
Sent: Wednesday, June 18, 2008 1:38:11 PM
Subject: [rabbit-semi] Re: Duplicate Acks
Google TCP window size
Bill
--- In rabbit-semi@ yahoogroups. com, Steve Trigero
>
> The duplicate ACKs are from the Rabbit. What is the "TCP window size"
> you mention?
>
> Steve
> ----- Original Message ----
> From: Bill_CT
> To: rabbit-semi@ yahoogroups. com
> Sent: Wednesday, June 18, 2008 9:28:20 AM
> Subject: [rabbit-semi] Re: Duplicate Acks
> --- In rabbit-semi@ yahoogroups. com, Steve Trigero
> >
> > When communicating via ethernet with an RCM3000, Wireshark reports
> duplicate ACKs
> > from the rabbit. Is this normal, a bug in the DC library, or maybe
> something I'm doing in
> > my application. How does one go about troubleshooting this?
>
> It's probably normal if it's the Rabbit sending them. It's one way to
> change the TCP window size to avoid congestion. This is likely
> happening because the Rabbit is slow and can't keep up at full link
> speed with a PC (which can run full speed). You should see the window
> size shrink and the dup acks become less frequent.
>
> If it's the PC sending them, I'm surprised.
>
> Be aware that WireShark can affect the bandwidth of the link it's
> "watching". Though at the speeds you're working with it's not likely
> to occur.
>
> Bill
>
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )