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A special congrats goes out to Issac on passing his CCSP!  Share his success with 30% off on Rack Rental Tokens, use code ISSAC from now through Friday July 23rd!

“Thanks for all of your help, I have obtained my CCSP Certification. This would have not be
possible without your support. I definitely look forward to your assistance as I pursue the CCIE Security Certification, thanks again.
 
see cisco partial congrat e-mail:
 
Dear Issac Grayson, Congratulations! You have earned your Cisco Career Certification. Your Cisco Certified Security Professional certificate is now available via the Certifications Tracking System.”

If you are like me, you want to take your knowledge of all the major Cisco Certification areas to at least the Professional level. For those intimidated by the VoIP track, have I got great news. One of the greatest Cisco Press titles ever written (in my biased and humble opinion) is the Voice over IP First-Step by my good friend and colleague Kevin Wallace.

While I was re-reading this book recently, I decided I would provide students with my list of Active Reading questions I developed. I would recommend you feed these into your SuperMemo app, or use one of the many Flash Card makers on the Internet if you are interested in mastering this exciting track.

Here are my queries from Chapter 1 Touring the History Museum of Telephony. For many blog readers, you might want to just challenge yourself with how many of these you can get without research. Enjoy!

POTS - But Nothing to Do With Marijuana

Questions Only

What does the acronym POTS stand for?

What is another term for a POTS telephone?

What does a telephone company’s CO stand for?

How many volts of power does the telephone company provide to a POTS phone using the wall jack?

What type of electrical current is used by the phone company to provide power to a POTS phone?

What phone jack is used in North America?

Of the six conductors in RJ-11, how many are actually used by a phone with a single line?

What are the two wires leaving your POTS phone called?

What is the POTS connection from your home to the local CO called?

In the POTS system, a connection from one phone switch to another phone switch in another CO is called what?

What does PSTN stand for?

What type of PSTN network typically includes local loop connections that provide a path for businesses and homes to connect back to the local CO?

What type of PSTN network typically interconnects local exchanges (for example, Class 5 offices) and tandem exchanges?

What type of PSTN network connects local exchanges with long-distance offices?

What does PBX stand for?

What is a telephone exchange that serves a business or office, as opposed to one that a common carrier or telephone company operates for many businesses or for the general public?

What is a multiline telephone system typically used in small office environments?

Name three types of phone call signaling.

Name three types of Supervisory Signaling.

What is Loop Start Signaling?

What is glare?

What is Ground Start Signaling?

What type of electrical current is used by Ringing?

What is Address Signaling?

What method of address signaling is used by a rotary phone?

What is a more efficient approach to address signaling when compared to pulse dialing?

Name four types of Information Signaling.

A Cisco Call Agent replaces many of the features of what traditional telephony device?

What VoIP device is used to forward calls between different types of networks?

The Cisco CallManager (CCM) is an example of what type of product?

What VoIP device can deny calls onto a WAN due to insufficient bandwidth?

What VoIP device is often used to assist with conference calling features?

What dedicated piece of computer circuitry is often used in an MCU?

How many channels are in a T1 line?

Questions and Answers

What does the acronym POTS stand for?

Plain Old Telephone Service

What is another term for a POTS telephone?

Analog Phone

What does a telephone company’s CO stand for?

Central Office

How many volts of power does the telephone company provide to a POTS phone using the wall jack?

-48

What type of electrical current is used by the phone company to provide power to a POTS phone?

DC (Direct Current)

What phone jack is used in North America?

RJ-11

Of the six conductors in RJ-11, how many are actually used by a phone with a single line?

Two

What are the two wires leaving your POTS phone called?

Tip and Ring

What is the POTS connection from your home to the local CO called?

Local Loop

In the POTS system, a connection from one phone switch to another phone switch in another CO is called what?

Interoffice trunk

What does PSTN stand for?

Public Switched Telephone Network

What type of PSTN network typically includes local loop connections that provide a path for businesses and homes to connect back to the local CO?

Local Network

What type of PSTN network typically interconnects local exchanges (for example, Class 5 offices) and tandem exchanges?

Exchange Area Network

What type of PSTN network connects local exchanges with long-distance offices?

Long-Haul Networks

What does PBX stand for?

Private Branch Exchange

What is a telephone exchange that serves a business or office, as opposed to one that a common carrier or telephone company operates for many businesses or for the general public?

PBX

What is a multiline telephone system typically used in small office environments?

Key System

Name three types of phone call signaling.

Supervisory, Address, and Information

Name three types of Supervisory Signaling.

Loop Start, Ground Start, and Ringing

What is Loop Start Signaling?

The switch at the CO seeing a home phone has gone off-hook thanks to the flow of current with the closing of the tip and ring circuit.

What is glare?

A situation where the trunk link is seized from both ends at the same time. In other words, you pick up the phone, and someone is already on the other end of the line.

What is Ground Start Signaling?

A modified form of Loop Start Signaling whereby there is current detection at both ends which is used to request and then confirm that the trunk is available before it is seized.

What type of electrical current is used by Ringing?

Alternating Current (AC)

What is Address Signaling?

This allows the phone to specify the “address” of the destination phone using dialed digits.

What method of address signaling is used by a rotary phone?

Pulse Dialing

What is a more efficient approach to address signaling when compared to pulse dialing?

Dual Tone Multifrequency (DMTF)

Name four types of Information Signaling.

Dial Tone, Ring Back, Busy Signal, Reorder Tone

A Cisco Call Agent replaces many of the features of what traditional telephony device?

PBX

What VoIP device is used to forward calls between different types of networks?

Gateway

The Cisco CallManager (CCM) is an example of what type of product?

Call Agent

What VoIP device can deny calls onto a WAN due to insufficient bandwidth?

Gatekeeper

What VoIP device is often used to assist with conference calling features?

Multipoint Control Unit (MCU)

What dedicated piece of computer circuitry is often used in an MCU?

Digital Signal Processors (DSP)

How many channels are in a T1 line?

24

Summer was in full swing, and it was over 105 degrees Fahrenheit outside.   Bob was told it was a “dry heat”, but he thought “so is my oven”.  Needless to say, Bob was glad to be in the data center, where the temperature and humidity controls kept it very cold.   He had been asked to setup up a basic route-map with BGP, and here is the diagram he worked from.

The goal, was to modify BGP,  so that all traffic going towards the 1.1.1.0 network (which is sourced from AS1), traveling either from or through AS23, would only use the 13.0.0.0/24 segment (between R3 and R1), and not use the 10.0.0.0/24 segment (between R2 and R1) as a transit path.
Bob reviewed some of the BGP topics he had recently learned.   Here is the list he made of possibilities:
R1 could pre-pend to the AS path for advertisements of the 1.1.1.0/24 prefix when it is sent to R2 from R1.   This way, AS23 would see a better path through R3 rather than R2.  He tried this using the following on R1:

ip prefix-list JUST-1.1.1.0 seq 5 permit 1.1.1.0/24

route-map PRE-PEND permit 10
 match ip address prefix-list JUST-1.1.1.0
 set as-path prepend 1
route-map PRE-PEND permit 20

router bgp 1
 neighbor 10.0.0.2 route-map PRE-PEND out

Bob cleared the BGP session, just to be sure.    Unfortunately, some traffic destined to 1.1.1.0 was still flowing over the 10.0.0.0 network between R2 and R1.

Bob decided to try another approach, and instead of R1 trying to make AS23 think the path on 10.0.0.0 was worse, perhaps he would tell R3 to make the path on 13.0.0.0 look better.    He considered weight, but then realized that would only work for R3, and not every other device in AS23.    So Bob decided to use local-preference.  On R3, he tried using local-preference, to specify that when a BGP update came in from R1 for 1.1.1.0, R3 would set the local-preference to 250 for that prefix, in hopes that this would allow traffic destined for 1.1.1.0 go exclusively through the 13.0.0.0 segment between R3 and R1.   Unfortunately, even with this change, Bob noticed that traffic destined to 1.1.1.0 from our through AS23 still crossed on the link between R2 and R1.

Below are the configurations for R1, R2 and R3 along with the relevant show commands.

Can you assist Bob?   What can he do?  What did he do wrong, if anything?

Post your ideas and comments below!

R1:

version 12.4
hostname R1
interface Loopback0
 ip address 1.1.1.1 255.255.255.0
 ip ospf network point-to-point

interface FastEthernet0/0
 ip address 10.0.0.1 255.255.255.0
 ip ospf 1 area 1

interface FastEthernet1/0
 ip address 13.0.0.1 255.255.255.0
 ip ospf 1 area 1

router bgp 1
 no synchronization
 bgp log-neighbor-changes
 network 1.1.1.0 mask 255.255.255.0
 neighbor 10.0.0.2 remote-as 23
 neighbor 10.0.0.2 route-map PRE-PEND out
 neighbor 13.0.0.3 remote-as 23
 no auto-summary

ip prefix-list JUST-1.1.1.0 seq 5 permit 1.1.1.0/24

route-map PRE-PEND permit 10
 match ip address prefix-list JUST-1.1.1.0
 set as-path prepend 1

route-map PRE-PEND permit 20

R2:

version 12.4
hostname R2
interface FastEthernet0/0
 ip address 10.0.0.2 255.255.255.0
 ip ospf 1 area 1

interface FastEthernet0/1
 ip address 23.0.0.2 255.255.255.0
 ip ospf 1 area 1

router bgp 23
 no synchronization
 bgp log-neighbor-changes
 neighbor 10.0.0.1 remote-as 1
 neighbor 23.0.0.3 remote-as 23
 no auto-summary
!

R3:

version 12.4
hostname R3
interface FastEthernet0/0
 ip address 13.0.0.3 255.255.255.0
 ip ospf 1 area 1

interface FastEthernet0/1
 ip address 23.0.0.3 255.255.255.0
 ip ospf 1 area 1

router bgp 23
 no synchronization
 bgp log-neighbor-changes
 neighbor 13.0.0.1 remote-as 1
 neighbor 13.0.0.1 route-map SET-LOCAL-PREF in
 neighbor 23.0.0.2 remote-as 23
 no auto-summary

ip prefix-list LOCAL-PREF-250 seq 5 permit 1.1.1.0/24

route-map SET-LOCAL-PREF permit 10
 match ip address prefix-list LOCAL-PREF-250
 set local-preference 250

route-map SET-LOCAL-PREF permit 20

Show commands R1:

R1#show ip bgp summary
BGP router identifier 1.1.1.1, local AS number 1
BGP table version is 2, main routing table version 2
1 network entries using 120 bytes of memory
1 path entries using 52 bytes of memory
2/1 BGP path/bestpath attribute entries using 248 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
Bitfield cache entries: current 1 (at peak 2) using 32 bytes of memory
BGP using 452 total bytes of memory
BGP activity 2/1 prefixes, 2/1 paths, scan interval 60 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.0.0.2        4    23      77      73        2    0    0 00:29:01        0
13.0.0.3        4    23      74      74        2    0    0 00:29:01        0

R1#show ip bgp
BGP table version is 2, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.0/24       0.0.0.0                  0         32768 i

R1#show ip route | begin resort
Gateway of last resort is not set

1.0.0.0/24 is subnetted, 1 subnets
C       1.1.1.0 is directly connected, Loopback0
23.0.0.0/24 is subnetted, 1 subnets
O       23.0.0.0 [110/2] via 13.0.0.3, 00:48:43, FastEthernet1/0
                 [110/2] via 10.0.0.2, 00:48:09, FastEthernet0/0
10.0.0.0/24 is subnetted, 1 subnets
C       10.0.0.0 is directly connected, FastEthernet0/0
13.0.0.0/24 is subnetted, 1 subnets
C       13.0.0.0 is directly connected, FastEthernet1/0

Show commands R2:

R2#show ip bgp summary
BGP router identifier 2.2.2.2, local AS number 23
BGP table version is 14, main routing table version 14
1 network entries using 120 bytes of memory
2 path entries using 104 bytes of memory
3/1 BGP path/bestpath attribute entries using 372 bytes of memory
2 BGP AS-PATH entries using 48 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
Bitfield cache entries: current 1 (at peak 2) using 32 bytes of memory
BGP using 676 total bytes of memory
BGP activity 1/0 prefixes, 4/2 paths, scan interval 60 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.0.0.1        4     1      73      77       14    0    0 00:29:07        1
23.0.0.3        4    23      71      73       14    0    0 01:04:54        1

R2#show ip bgp
BGP table version is 14, local router ID is 2.2.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

Network          Next Hop            Metric LocPrf Weight Path
*>i1.1.1.0/24       13.0.0.1                 0    250      0 1 i
*                   10.0.0.1                 0             0 1 1 i

R2#show ip route | begin resort
Gateway of last resort is not set

1.0.0.0/24 is subnetted, 1 subnets
B       1.1.1.0 [200/0] via 13.0.0.1, 00:28:37
2.0.0.0/24 is subnetted, 1 subnets
C       2.2.2.0 is directly connected, Loopback0
23.0.0.0/24 is subnetted, 1 subnets
C       23.0.0.0 is directly connected, FastEthernet0/1
10.0.0.0/24 is subnetted, 1 subnets
C       10.0.0.0 is directly connected, FastEthernet0/0
13.0.0.0/24 is subnetted, 1 subnets
O       13.0.0.0 [110/2] via 23.0.0.3, 00:48:16, FastEthernet0/1
                 [110/2] via 10.0.0.1, 00:49:19, FastEthernet0/0

Show commands R3:

R3#show ip bgp summary
BGP router identifier 3.3.3.3, local AS number 23
BGP table version is 6, main routing table version 6
1 network entries using 120 bytes of memory
1 path entries using 52 bytes of memory
3/1 BGP path/bestpath attribute entries using 372 bytes of memory
1 BGP AS-PATH entries using 24 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
Bitfield cache entries: current 1 (at peak 2) using 32 bytes of memory
BGP using 600 total bytes of memory
BGP activity 1/0 prefixes, 5/4 paths, scan interval 60 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
13.0.0.1        4     1      74      74        6    0    0 00:29:09        1
23.0.0.2        4    23      73      71        6    0    0 01:04:56        0

R3#show ip bgp
BGP table version is 6, local router ID is 3.3.3.3
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.0/24       13.0.0.1                 0    250      0 1 i

R3#show ip route | begin resort
Gateway of last resort is not set

1.0.0.0/24 is subnetted, 1 subnets
B       1.1.1.0 [20/0] via 13.0.0.1, 00:28:39
3.0.0.0/24 is subnetted, 1 subnets
C       3.3.3.0 is directly connected, Loopback0
23.0.0.0/24 is subnetted, 1 subnets
C       23.0.0.0 is directly connected, FastEthernet0/1
10.0.0.0/24 is subnetted, 1 subnets
O       10.0.0.0 [110/2] via 23.0.0.2, 00:48:18, FastEthernet0/1
                 [110/2] via 13.0.0.1, 00:48:48, FastEthernet0/0
13.0.0.0/24 is subnetted, 1 subnets
C       13.0.0.0 is directly connected, FastEthernet0/0

Best wishes,

Keith

And the answer is:

Thanks to you, and your 50+ posts, bob got his answer.   By reading your responses, Bob learned the following:

For R2, the BGP next hop for the best route, is still 13.0.0.1, even though it is learned from R3.     R3 doesn’t bother to change the next-hop attribute when learning routes via a eBGP neighbor (R1).    With R2 having 2 equal cost paths (OSPF) for the next hop of 13.0.0.1, R2 would load balance the traffic over the 10.0.0.0 and 23.0.0.0 networks for traffic going to 1.1.1.0/24

One solution would be to have R3 use next-hop-self for updates sent to R2.  Then R2 would see the next hop as 23.0.0.3, and all the traffic would be forwarded to R3 as desired.

The update on R3 would look like this:

router bgp 23
 neighbor 23.0.0.2 next-hop-self

This would cause R2, to have the BGP table of this:

R2#show ip bgp
BGP table version is 4, local router ID is 2.2.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

Network          Next Hop            Metric LocPrf Weight Path
*>i1.1.1.0/24       23.0.0.3                 0    250      0 1 i
*                   10.0.0.1                 0             0 1 1 i

Another option would be increasing the OSPF cost on R2’s 10.0.0.0/24 interface, so that it wouldn’t be considered an equal cost to get to 13.0.0.1 (the previous next hop before the change we just made).

Thanks everyone for all your assistance!    You rock.

Join us Friday, June 25th at 11AM Pacific / 2PM Eastern for another installment in the Open Lecture Series.

The topic that will be covered is Privilege Levels and Role Based CLI.

We look forward to seeing you there. Seats are limited.

Starting July 1st, we are introducing downloadable content for the CCSP and CCVP bootcamp class-on-demand courses.  This exciting new addition will come as a warm welcome to all those looking to have the world’s best training programs on the go.  These courses will be offered in .m4v video format and work seamlessly on the iPhone, iPad, and other mobile devices as well as on your desktop.  We will be providing a upgrade option for everyone who currently has these classes as well as a product add-on to those who have held out for this option.  The upgrade price will be just $49.95 and give you the freedom to watch Flash free content wherever you go.

There is even more good news! If you purchase either the CCSP Bootcamp Class-on-Demand or the CCVP Bootcamp Class-on-Demand between now and July 1st, you will receive this upgrade at no additional cost, and the downloadable version will be added to your account on July 1st.

In this short blog post, we are going to give condensed overview of the four main flavors of Frame-Relay Traffic Shaping (FRTS). Historically, as IOS evolved with time, different methods have been introduced, having various level of feature support. Two main features, specific to Frame-Relay Traffic-Shaping are per-VC shaping and queueing and adaptive shaping in response to Frame-Rleay congestion notifications (e.g. BECNs). You’ll see that not every flavor supports these two features. We begin with the «fossil» known as Generic Traffic Shaping.

Generic Traffic Shaping

This feature was initially designed to shape packet traffic sent over any media, be it Ethernet, Frame-Relay, PPP etc. The command syntax is traffic-shape {rate|group} and allows specifying traffic scope using an access-list (notice that different ACL types are supported). You may tune the Bc/Be values as well as the shaping queue depth (amount of buffers). If the shaper delays traffic, the queue service strategy would be fixed to WFQ with the queue size equal to the buffer space allocated. Additional WFQ parameters such as number of flows and congestive discard threshold could not be tuned and set based on the shaper rate automatically.

An unique feature of GTS is the ability to apply multiple shapers to a single interface. However, shapers are not cascaded, but rather a packet is assigned to the first matching shaper rule. In the example below, there are three rules, with the last one being “fallback”, matching all packets that didn’t match access-lists 100 and 101. Unlike using the legacy CAR feature (rate-limit command) you cannot «cascade» multiple traffic-shape statements on the same interface.

traffic-shape group 100 128000
traffic-shape group 101 64000
traffic-shape rate 256000

You cannot apply GTS per-VC unless you have created a subinterface for this particular PVC. You may, however, enable shaping that adapts to FR BECNs, using the syntax traffic-shape adaptive {rate} along with traffic-shape rate. Notice that if multiple PVCs map to interface, reception of a BECN on any of the VCs will trigger speed throttling.

Legacy Frame-Relay Traffic-Shaping

This feature uses the map-class frame-relay syntax and was initially designed to implement specifically Frame-Relay Traffic Shaping and Policing (FRTS and FRTP) in Cisco IOS routers. This is still probably the most widely used form of FRTS. You specify all parameters under a map-class and then apply this map-class to a specific PVC or interface using the syntax similar to the following:

map-class frame-relay DLCI_101
 frame-relay cir 256000
 frame-relay bc 2560
 frame-relay be 0
 frame-relay mincir 192000
 frame-relay adaptive-shaping becn
!
interface Serial 0/0
 frame-relay traffic-shaping
!
interface Serial 0/0.1
 frame-relay interface-dlci 101
  class DLCI_101

A mandatory command that goes with Legacy FRTS is frame-relay traffic-shaping applied to an interface (there is also frame-relay policing command to implement traffic policing). With this command applied, all PVC CIRs are set to default 56Kbps unless you change that value in a map-class that you apply. Additionally, interface software queue is turned into FIFO, and every PVC gets its own, second-level, logical queue realized as shaper’s queue. Therefore, FRTS enables “true” FRTS by allowing for two-level queueing hierarchy.

Legacy FRTS allows for various queueing methods on per-VC level. You may use any of legacy techniques such as Custom Queueing, Priority Queueing, FIFO and WFQ/IP RTP Priority. More importantly, you may enable CBWFQ on per-VC level, by using the map-class command service-policy output along with the policy-map implementing CBWFQ logic. Note that if you apply CBWFQ per-VC, the maximum avaiable bandwidth is based on minCIR settings for a VC, not the CIR.

All the above QoS mechanisms could be combined with Per-VC fragmentation enabled solely by using the map-class command frame-relay fragment. Normally, you need to enable fragmentation on every PVC terminated on the interface, so make sure you configure all map-classes properly. As soon as fragmentation is enabled, the interface-level FIFO queue is turned into special «truncated» Priority Queue used for interleaving fragments and voice packets. Only High and Normal queues out of the PQ are used to implement interleaving and you can inspect queue utilization using the command show queueing.

Obviously enough, you cannot use GTS on the same interface where FRTS has been enabled and vice-versa – IOS will reject the command. Compared to GTS, legacy FRTS provide a lot of syntactical consistency – you apply all features using the map-class commands plus you have a rich selection of QoS mechanisms along with that.

(BTW, if you’re wondering the purpose of frame-relay tc command under a map-class, it is used in zero-CIR scenarios for traffic policing. With zero-CIR policing all traffic is considered exceeding, but you may want to specify the peak rate by setting Be and Tc together).

MQC Frame-Relay Traffic-Shaping

This was Сisco’s attempt to leverage MQC syntax for the purpose of traffic-shaping. The problem was that the syntax is still combined with the “legacy” style map-class syntax. Here’s how it works:

• You create a «first-level» policy-map implementing shaping for a VC. You can only use «class-default» at this level, and apply shaping parameters using the commands shape average, shape peak, and shape adaptive. For example:

  policy-map SHAPE
   class class-default
      shape average 512000 5120 0
      shape adaptive 256000
  

• You create «nested» or «second-level» policy that implements CBWFQ. Note that CBWFQ/LLQ is the only queueing method supported with MQC-based FRTS (no CQ or PQ allowed, though you can emulate WFQ using MQC syntax).

  policy-map CBWFQ
    class VOICE
     priority 128
    class class-default
     fair-queue
  

• Combine both policy-maps and attach the parent policy to a map class. You should not enable the interface-level command frame-relay traffic-shaping with MQC FRTS.

  policy-map SHAPE
    class class-default
     service-policy CBWFQ
  !
  map-class frame-relay DLCI_101
    service-policy output SHAPE
  !
  interface Serial 0/0.1
    frame-relay interface-dlci 101
     class DLCI_101
  

From the above configuration example it is apparent that PVC shaping settings are now defined using the MQC shape average and shape adaptive commands. Similar to the use of CBWFQ with legacy FRTS, available CBWFQ bandwidth is based on the shape adaptive setting. Also, as mentioned before, you should not use the command frame-relay traffic-shaping with MQC FRTS. In fact, legacy FRTS and MQC FRTS are incompatible.

Frame-Relay Fragmentation (FRF.12) is supported with MQC FRTS, however you have to enable it at the interface level using the command frame-relay fragment X end-to-end. Interleaving queue is created automatically and cannot be seen using IOS show commands. Fragmentation is enabled on all PVCs terminated at the interface.
Compared to legacy FRTS, the MQC equivalent has some unique features, known as «Voice Adaptive Shaping» and «Voice Adaptive Fragmentation». The first feature activates adaptive shaping when packets are detected in the LLQ queue (if there is one configured) and the second feature activates fragmentation under the same condition of traffic present in the LLQ. The first feature is useful in oversubscription scenario, where you want to slow down from peak rate to committed rate when sending VoIP traffic to ensure better voice quality. The second feature is more useful, and allows you enabling traffic fragmentation only when it’s really needed, i.e. when a voice calls is active.

Class Based Generic Traffic Shaping (CB-GTS)

The last method is based purely on MQC syntax using the generic commad shape average. In many senses, it’s similar to the legacy GTS but uses newer syntax and supports more granular application. Have a look at the following example:

policy-map SHAPE_DLCI_101
  class class-default
   shape average 256000
!
! You can match DLCI's in class-maps
!
class-map DLCI_202
 match fr-dlci 202
!
policy-map SHAPE_DLCI_202
!
policy-map INTERFACE_POLICY
  class DLCI_202
   service-policy SHAPE_DLCI_202
!
interface Serial 0/0
  service-policy output INTERFACE_POLICY
!
interface Serial 0/0.1
  frame-relay interface-dlci 101
  service-policy output SHAPE_DLCI_101

The above example shows you two approaches to implementing VC-specific shaping. The first one uses a specific subinterface and the second one uses a class-map matching specific DLCI. The first method more reminds the legacy GTS, while the second allows pushing all VC policy under a single policy-map. Of course, you can always nest another MQC policy under a shaped class and implement CBWFQ and/or traffic marking/policing, just like you would do with any normal MQC configuration. FRF.12 fragmentation is also supported by means of the interface-level command frame-relay fragment, the same used with MQC FRTS.

Now for the CB-GTS limitation. There is a bunch, unfortunately. first of all, adaptive shaping does not work with CB-GTS i.e. the command shape average does not have any effect. Secondly, you may enable fragmentation at the interface level, but you cannot use any of MQC-based FRTS features, such as voice-adaptive fragmentation and shaping. Therefore, CB-GTS is not exactly a Frame-Relay Traffic Shaping solution, though it allows for generic shaping on per-VC basis.

Summary

As IOS software was evolving, multiple approaches to FRTS have been developed. Possibly the most commonly used one nowaday is Legacy FRTS, which supports practically all features with except to adaptive shaping/fragmentation availabled with MQC FRTS only. Even though from today’s perspective MQC CB-GTS seems to be the most reasonable method, it does yet lack support of such important feature as adaptive shaping. It’s up to you to select the best method, but be aware of their limitations.

I just returned from an awesome Security bootcamp in Raleigh, and am looking forward to more there in the future. Core knowledge is still alive and well in the Security LAB exam, as well as troubleshooting, which is integrated as part of the configuration section.

Often times, what seem like complex network troubleshooting scenarios are caused by overlooking simple fundamental components of the technology. Join me on Tuesday, June 8th as we discuss developing the Tier 1 knowledge that you need to know for the CCIE Security LAB, as well as strategy that may be used to continually build your base of knowledge as you prepare for your CCIE certification.

This v-Seminar is open to the public, and will be held online at

To sign up for v-Seminars, click here, and select the link for Free v-Seminars.

To join the meeting listed above, click here now.

See you soon!

Keith

As my 4-year recertification timeline was about to lapse, I had to go and pay $350 to recertify There was no other challenge, as I picked CCDE written for recertification, keeping in mind to take the practical test again this year. To my greatest surprise, the exam was almost the same it was in September 2007, when I took the beta version. Just this time the number of questions was 100 not 170 and they give you chance to review and navigate among the questions (just like it was in old CCIE Written). Apparently, the CCDE written test engine has never been updated the way that CCIE R&S Written was, with the new scoring model based on 1000 points. Since 2007 I spent considerable amount of time studying (back then I went unprepared, but still passed with 70 point) so the exam went disappointedly easy, as I haven’t seen anything new that I didnt see in 2007. As usual, the main focus is on IP Routing with the addition of Tunneling techniques (MPLS, GRE, IPSec) along with QoS, Network Management and Network Security. You may find the very detailed blueprint here (though formatting is broken in a number of places):

http://www.cisco.com/web/learning/le3/ccde/ccde_exam_information.html

The books I found most helpful to prepare were:

- Definitive MPLS Network Designs
- BGP Design and Implementation
- IS-IS: Deployment in IP Networks
- OSPF: Anatomy of an Internet Routing Protocol
- Optimum Routing Designs (you may mainly concentrate on IGP protocols and refer to the book above for BGP)
- EIGRP for IP: Basic Operation and Configuration
- Cisco IP Routing by Alex Zinin (for you hardcore routing fans)
- OSPF and ISIS: Choosing and IGP for Large Scale Network
- Layer 2 VPN Architectures
- Interconnections, 2nd edition: Bridges, Routers, Switches and Internetworking Protocols. (Just for fun reading and a lot of background information)

Lastly, anyone preparing for the CCDE certification – even though the written test is easy, do not take it lightly as you’ll need all the knowledge during the practical test. There are other challenges in the practical exam, but hopefully the plan I developed to deal with that will work for me – we’ll see

We’re pleased to announce the launch of INE’s redesigned blog.  We have tried to update the blog design so that it looks clean,current and resembles the new INE.com.  Besides just a new look, we now include our Twitter feed at the bottom of every page along with links to find INE throughout the web.  Categories have been moved to the right side of the page in the dropdown box and information about each CCIE instructor is added at the end of their blog posts.  If you have any comments or feedback on the redesign please post them below.

Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.

We are excited to announce that for the first time INE is traveling to Nigeria! In partnership with New Horizons, INE will be offering two classes in Lagos, Nigeria. We will be offering both our CCIE Routing & Switching Advanced Technologies Class and our CCIE Security Advanced Technologies Class. These classes will be held in New Horizons Training centers.

Both classes will be held from May 3-7, 2010. Both classes will be tentatively held May 24 – 28, 2010.  Keith Barker, CCIE#6783 (R&S, SC), will be teaching the CCIE Routing & Switching Advanced Technologies Class and Marvin Greenlee, CCIE#12237 (R&S, SC, SP), will be teaching the CCIE Security Advanced Technologies Class.

For additional information on classes held in Nigeria:

Email:

Class/Sales Information

Mr. Oluwaseyi Ojo

oluwaseyi@newhorizonsnigeria.com

Class/Information Hotlines:

Seyi: 234-7030160944 or Edward: 234-8073809974

New Horizons Nigeria General:

234-1-7901013 or 234-1-8976386

INE is looking forward to providing training in a new location! For more information on the Advanced Technologies Class please visit our website.

Routing & Switching Advanced Technologies Class

Security Advanced Technologies Class