frame relay traffic shaping

[espmolina]

In frame relay traffic shaping;

- is CIR the committed BW from the service provider.

I am contemplating of applying for an FR service but I do not what to ask. I need to connect 2 sites. Maybe I can start off with a 64Kbps between the 2. Would that mean I should apply for a 64 Kbps CIR? What about the Be and Bc?

Any help will be appreciated.

[Georg Pauwen · Accepted solution]

Hello,

typically, a Frame Relay provider would guarantee half of the CIR. So, if you ask for a 64K circuit, 32K would be guaranteed, the rest of the traffic would be marked as 'discard eligibible, or DE', which means that in case of congestion, the traffic would be dropped.

Regarding the Be and Bc values: the Bc value is related to the configured CIR. If you want to apply FR Traffic Shaping for your 64K circuit, it would look like this:

frame-relay cir 64000

frame-relay bc 8000

The value 8000 is derived from the formula:

Bc=CIR*Tc

The default TC is 0,125, which equals 1/8 of a second. You might want to check the following document for an excellent explanation of the different values, and how they interact:

Frame Relay Traffic Shaping

http://www.internetworkexpert.com/resources/01700368.htm

By the way, once you have your circuit in place, you can use the 'show frame-relay map' command to verify that you are actually getting the bandwidth that you have ordered. In the output of that command, look for the line 'BW=', that is the bandwidth configured.

ISP's sometimes 'forget' to set that bandwidth correctly...

HTH,

GP

[espmolina]

Thanks very much.

I was wondering though. When is generic traffic shaping used?

Thanks again.

[espmolina]

Follow up question:

How is configured CIR related (fram-relay cir <>) to the configured bandwidth (bandwidth <>)?

Thanks again.

[Georg Pauwen]

Hello,

the bandwidth command configured on an interface and the CIR are not related, the bandwidth command is usually configured for routing protocols such as EIGRP.

As for GTS (Generic Traffic Shaping), you can inded use that for Frame Relay as well. Check the following document for a discussion and when you would use GTS and when FRTS:

Traffic Shaping

http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800bd8ed.html#wp1001072

Regards,

GP

[espmolina]

The traffic-shaping parameter definition at both end need not be the same, right?

Thanks again.

[dandaluz]

Hi,

Couple of Thoughts on this:

1. The frame carrier's CIR is the guaranteed bandwidth for your connection. You could order a T-1 Port with a 768K CIR. The provider will guarantee you 768K. Anything sent above that would be discard eligible. Obviously, you can burst past the CIR, but this traffic is not guaranteed. This is how they all do it.

2. CIR is the speed at which you want to send traffic out of an interface. For example, if you have one site with T-1 access sending to a site with 256K access, you want to send at 256K from the T-1 site. Otherwise the 256K end gets overrun. All FRTS is doing is delaying traffic. FRTS sends traffic in intervals which you configure. If no space is available in one interval, traffic must wait for the next interval. That is a great link that was posted above.

And yes, Bandwidth and CIR are not related. BW is used for certain routing protocol metrics (EIGRP, IGRP, OSPF). And CIR is the speed at which you want to send traffic. If you're nesting a policy map inside of a frame map class it will use the interface bandwidth for certain settings within the policy map.

hope this helps.

Danny

[paltel]

For the bandwidth command, assume that i have a remote site (F.R with speed 256kbps), and i applied the following at the remote site router:

policy-map shaping

class one

bandwidth percent 30

class two

bandwidth percent 30

class three

bandwidth percent 10

class class-default

fair-queue

And applied this policy at the interface (out), when i issued the show policy-map interface ....

router#show policy-map interface serial 0/0/0

Serial0/0/0

Service-policy output: testing

Class-map: one (match-all)

0 packets, 0 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: protocol http

Queueing

Output Queue: Conversation 265

Bandwidth 30 (%)

Bandwidth 463 (kbps) Max Threshold 64 (packets)

(pkts matched/bytes matched) 0/0

(depth/total drops/no-buffer drops) 0/0/0

Class-map: two (match-all)

0 packets, 0 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: protocol ftp

Queueing

Output Queue: Conversation 266

Bandwidth 30 (%)

Bandwidth 463 (kbps) Max Threshold 64 (packets)

(pkts matched/bytes matched) 0/0

(depth/total drops/no-buffer drops) 0/0/0

Class-map: three (match-all)

0 packets, 0 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: protocol dns

Queueing

Output Queue: Conversation 267

Bandwidth 10 (%)

Bandwidth 154 (kbps) Max Threshold 64 (packets)

(pkts matched/bytes matched) 0/0

(depth/total drops/no-buffer drops) 0/0/0

Class-map: class-default (match-any)

5 packets, 185 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: any

Queueing

Flow Based Fair Queueing

Maximum Number of Hashed Queues 256

(total queued/total drops/no-buffer drops) 0/0/0

You see 30% of the bandwidth is 463kbps which means the available banwidth 1543 kbps.

-------------

If we set the bandwidth command to 256

it looks like

router#show policy-map interface serial 0/0/0

Serial0/0/0

Service-policy output: testing

Class-map: one (match-all)

0 packets, 0 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: protocol http

Queueing

Output Queue: Conversation 73

Bandwidth 30 (%)

Bandwidth 76 (kbps) Max Threshold 64 (packets)

(pkts matched/bytes matched) 0/0

(depth/total drops/no-buffer drops) 0/0/0

Class-map: two (match-all)

0 packets, 0 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: protocol ftp

Queueing

Output Queue: Conversation 74

Bandwidth 30 (%)

Bandwidth 76 (kbps) Max Threshold 64 (packets)

(pkts matched/bytes matched) 0/0

(depth/total drops/no-buffer drops) 0/0/0

Class-map: three (match-all)

0 packets, 0 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: protocol dns

Queueing

Output Queue: Conversation 75

Bandwidth 10 (%)

Bandwidth 25 (kbps) Max Threshold 64 (packets)

(pkts matched/bytes matched) 0/0

(depth/total drops/no-buffer drops) 0/0/0

Class-map: class-default (match-any)

35 packets, 1045 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: any

Queueing

Flow Based Fair Queueing

Maximum Number of Hashed Queues 64

(total queued/total drops/no-buffer drops) 0/0/0

which is right?

My question if we missed the banwidth command the configuration will be correct?

[paltel]

Another question, we need to configure each DLCI map-class parameters before we implement frame-relay traffic-shaping command at the main F.R interface, cause. i have many remote sites connected through this F.R E1 and if i will apply this command all the DLCI will be to default CIR value which is 56kbps, right?