Using QoS LLQ to prioritise your video and voice traffic

It has been a good week for me in terms of studying for the CCDA and at work. Learned a lot of new things such as QoS particularly LLQ and Pseudowire over Cisco’s ME. This blog I will focus more into QoS. Low-latency queing is a QoS feature developed by Cisco applying stricter policy queing  to Class-based weighted fair queing (CBWFQ).

LLQ is best applied when you have a network that has video and voice running. We know that they are very sensitive to jitter/delay. You have to make sure that voice/video packets gets preferential treatment over data. In my scenario, I have a customer who has a 881 Cisco router on-site that needed to connect to their VoIP system on a data center.

The requirements are to mark video traffic with af31 and voice with ef. Both are to have 10 percent each of the traffic bandwidth which is 20Mbps. Voice and video are on vlan 10. I am marking traffic as they go into the LAN interface and set classify and prioritize traffic as they go out of the WAN.

class-map match-any video-traffic
match dscp af31
class-map match-any voice-traffic
match dscp ef

policy-map WAN-EDGE-OUT
class voice-traffic
priority percent 10
class video-traffic
priority percent 10
class class-default
interface FastEthernet4
band 20000
ip nbar protocol-discovery
service-policy output WAN-EDGE-OUT

! LAN Interface QoS To MARK Traffic.

ip access-list extended CISCO
permit ip any any

class-map match-any MARKING-video-traffic
match access-group name CISCO

class-map match-any MARKING-voice-traffic
match protocol rtp

policy-map MARK-TRAFFIC
class MARKING-voice-traffic
set dscp ef
class MARKING-video-traffic
set dscp af31
Interface vlan 10
ip nbar protocol-discovery
Service-policy input MARK-TRAFFIC

Pretty neat stuff….you noticed I activated ip nbar protocol-discovery. To know more about that command, I have another blog regarding it.

Booked my CCDA exam and QoS

This evening I just made it official, booked the exam for the Cisco Certified Design Associate exam set in two months. That means I will be forced to be in study over-drive mode. Unlike the previous exams, things are different in the way that I don’t have extra time in my hands. I do work almost more than 8 hours a day, unlike last year when I was teaching I get lots of breaks and opportunities to study.

To be fair, at least I work with Cisco devices every single day. Speaking of Cisco devices, I have configured my first live QoS service for a customer. Customer wanted to do LLQ using dscp EF and AF31 for voice and video. I will probably post my configs here on a future blog…like tomorrow:) but we’ll see. It was amazing.

Initial thoughts on CCDA 640-864

So far I am pleased with how my studies have been going. Going deeper into Cisco’s CCDA track. I am watching again all CBTNuggets videos again, I have seen them last year but was just not paying much attention back then. I have gone through a couple of pages of the Cisco Press book. Honestly, so far it has been looking like a marketing track for me studying different Cisco products out there such as IBNS, TrustSec, MediaNet etc.

I think I was a little idealistic hoping this track would be delve more into the design aspect of the network and less of cisco’s products and technology. What was I thinking, its cisco of course they’ll be pushing alot of their technologies into the course. Nonetheless, I still learned a lot in terms of the Enterprise Campus design and project management aspect of building a network.

Familiar topics such as PPDIOO, IPv4, IPv6, spanning-tree particularly emphasis on the use of PV +RSTP and of course your IGPs such as OSPF and EIGRP. Yeah they have touched on BGP and ISIS.

I maybe shooting for the stars but I am hoping to get this exam by the end of the month. hopefully but we’ll see. We are currently one engineer short in Provisioning at work, so logically I should have more provisioning tasks within the month.

For those who are interested what have I been using for my CCDA studies, they are as follows:

  • CCDA training from CBTNuggets by Anthony Sequeira
  • CCDA Cisco Press Anthony Bruno, Steve Jordan (heavy reading TBH)

For labs, uhm I think I will just stick with GNS3 as I do not have enough gear to do VOIP labs.

Going deep and wide with CCDA

I noticed whenever I passed a certification such as what I got 2 days ago (BCvRE), I am such in a good mood to go after the next one. Yes, I will admit I am a cert junkie. Yes, I did claim that I will be doing my CCIE R&S soon but for some reason I had a change of heart.

I remember Keith Barker from CBTNuggets was asked regarding getting certs or how you should go about learning IT. He said something that I always remember “Go deep and wide”. I think Jeremy Cioara mentioned the same thing. I decided before going really deep into CCIE R&S, I wanna go wider this time and do a ladder approach getting my number.

I have decided to take the design track, meaning I will be taking the Cisco Certified Design Associate (CCDA) test which will eventually lead to the Cisco Certified Design Professional (CCDP). CCDP requires 3 exam, Route, Switch and Arch. I already have the first tue from my CCNP R&S.

I have gone through CBTNugget videos last year by Anthony Sequeira. I honestly feel its not enough, brutally saying I would have preferred Keith or Jeremy doing them. So here we go, I plan to take the first of two exam in 4 months. I will be updating my blog site for things I will be learning….that’s if I get the chance.

Passed Brocade Certified vRouter Engineer (BCvRE) exam.


Today I sat or should I say, did my re-take on the Brocade Certified vRouter Engineer exam this morning. Finally I passed. I took this exam a few months ago last year and failed in a screaming heap. It was a humbling experience, thinking back then that my CCNP R&S would be enough to pass the exam. Boy I was wrong.

The materials that Brocade provided was more of a marketing brochure as suppose to a resource paper. If you have your CCNA, it would definitely be an advantage. However, you just have to watch out for Brocade specific technology such as licensing, how they perform ACL, NAT and firewall. If you have exposure to Junos, I think that will definitely be an advantage as Vyatta and Junos has that BSD foundation.

I would suggest if you plan to take the same exam in the future or if you are currently studying for it, still go through the on-line course. But I am telling you, its not complete, you have to go through other resources such as the Vyatta/Brocade websites for the PDFs.

If you have a CCNA/CCNP, focus on Vyatta’s NAT, Firewall and Licensing/upgrade stuff as the rest you can easily figure out. I have a mate who is also a CCNP R&S but failed the same exam. We both share the same thoughts on what we needed to focus on.

What’s next? We have someone from Brocade who’ll be coming over at work to give us a training. He’s claiming that he will be covering BCNE. Brocade Certified Network Engineer, which is equivalent to Cisco’s CCNA R&S. We’ll have to see what will happen if it indeed would be enough to pass the exam. It’s always nice to have another cert on your belt.

Also since I am in the topic of Brocade, I will be flying over to Sydney next week with my team lead. Will be installing a couple of Brocade 6610 ICX switches in our rack at Equinix DC. That would be interesting.