Leased Line Circuit Presentations

Curiosityx · 16 Jan 2009 at 10:42

Greetings, im looking to compile a list of commonly used circuit presentations for leased lines installations, im well aware that circuits upto 2Mb/s are generally presented on X.21 interfaces and that one's on 10/100Mb bearers are generally always ethernet, the troublesome bracket appears to be the 2 - 8Mb/s range.

Are people seeing ethernet being used more often or are you ISP's still using technologies such as PPP Multilink for example?

Regards

Seaniboy · 16 Jan 2009 at 11:10

Used x.21 on our 2mb line. With 4mb a new SAN/WAN extenstion was put in with a Les10 card which has the normal 2 fibre links and ethernet as the presentation

bigredshark · 16 Jan 2009 at 15:33

I'd be surprised if anything is put in as anything other than ethernet these days, the main presentation issue is copper or fibre. you might see various e1 presentations for 2mb and lower circuits but none of the ISPs I've worked for would touch multilink for the 2-8mb area, it's as or more expensive than Ethernet and there's more to go wrong.

Curiosityx · 16 Jan 2009 at 21:02

Cheers for the replies guys.

Curiosityx · 18 Jan 2009 at 12:51

Can i ask do you guys ever terminated ethernet connections directly on the back of your firewall appliances, ive always tended to use an 1800 or 2800 router for such purposes but im trying to find a valid reason not to in order to reduce overall cost of some deployments.

sidethink · 19 Jan 2009 at 09:23

I suppose it depends on whether your provider needs to see a router on the end of the circuit. Certainly for the older LES type circuits we wouldn't route first.

Often though, the router is the endpoint of the provider's network - as long as you can get around these issues and there is clear demarcation you can attach it however you want to.

bigredshark · 19 Jan 2009 at 11:05

Curiosityx said:
Can i ask do you guys ever terminated ethernet connections directly on the back of your firewall appliances, ive always tended to use an 1800 or 2800 router for such purposes but im trying to find a valid reason not to in order to reduce overall cost of some deployments.

Yes, frequently. LES directly into the untrust interface on the firewall. The only reason I'd ever put both a router and a firewall in is if

a) the connection was terminated in some way it couldn't be directly connected to the firewall (rare these days, ADSL/SDSL/E1 modules are all available for the firewalls so it'd need to be really exotic like a STM1 or something)

b) we're running a backup connection with some fancy routing. I don't like more advanced BGP/OSPF routing on firewalls if I can avoid it, best left to a dedicated router.

EDIT: I'd add, I use Juniper firewalls pretty exclusively, they now have a fairly impressive range of modular interfaces. Cisco really lags behind with the ASA in this area, probably because they'd like you to buy a router too...

Curiosityx · 21 Jan 2009 at 00:18

bigredshark said:
Yes, frequently. LES directly into the untrust interface on the firewall. The only reason I'd ever put both a router and a firewall in is if

a) the connection was terminated in some way it couldn't be directly connected to the firewall (rare these days, ADSL/SDSL/E1 modules are all available for the firewalls so it'd need to be really exotic like a STM1 or something)

b) we're running a backup connection with some fancy routing. I don't like more advanced BGP/OSPF routing on firewalls if I can avoid it, best left to a dedicated router.

EDIT: I'd add, I use Juniper firewalls pretty exclusively, they now have a fairly impressive range of modular interfaces. Cisco really lags behind with the ASA in this area, probably because they'd like you to buy a router too...

Cheers for that, do you apply the same methodology when working from a QoS perspective? Ive little experience on Juniper equipment but the ASA's do support LLQ, Shaping and Policing which one would assume can be taken advantage of when not using said router to terminate an ethernet connection.

I very much agree on the comments made in regards to the lack of module support, bar additional ethernet and fiber interfaces there isnt a lot of choice at all.

Regards

bigredshark · 21 Jan 2009 at 10:11

Curiosityx said:
Cheers for that, do you apply the same methodology when working from a QoS perspective? Ive little experience on Juniper equipment but the ASA's do support LLQ, Shaping and Policing which one would assume can be taken advantage of when not using said router to terminate an ethernet connection.

I very much agree on the comments made in regards to the lack of module support, bar additional ethernet and fiber interfaces there isnt a lot of choice at all.

Regards

Generally yes, the QOS is pretty good on the SSG range. However, being a service provider we also have the option to implement QOS on the access router at the other end as most 'last mile' connections are uncontended for us.