Hi, I know this is not suse related, but i think someone here can answer my question concering a backup line for t1. I have a store and it needs to communicate with an outisde server and be on the net. I heard that a t1 is suppose to be up 99.9 percent of the time, so is it necessary to have a backup, maybe like an isdn? Has anyone experienced a t1 going down? thanks henry
Henry Tang said:
Hi,
I know this is not suse related, but i think someone here can answer my question concering a backup line for t1. I have a store and it needs to communicate with an outisde server and be on the net. I heard that a t1 is suppose to be up 99.9 percent of the time, so is it necessary to have a backup, maybe like an isdn? Has anyone experienced a t1 going down?
thanks henry
Henry, We have lots of T1's here and we've had them go down a few times due to problems with the phone company. An ISDN backup is one alternative that could work, although ISDN can be expensive since you normally pay per minute. Another option might be to have a DSL connection and use something like HSRP (Hot Standby Router Protocol, which is a proprietary Cisco solution). What kind of hardware are you using? Does the T1 connect you to the internet, or is it used as a point-to-point to connect to an internal network somewhere? Chris
Henry,
We have lots of T1's here and we've had them go down a few times due to problems with the phone company. An ISDN backup is one alternative that could work, although ISDN can be expensive since you normally pay per minute. Another option might be to have a DSL connection and use something like HSRP (Hot Standby Router Protocol, which is a proprietary Cisco solution). What kind of hardware are you using? Does the T1 connect you to the internet, or is it used as a point-to-point to connect to an internal network somewhere?
Chris
Hi chris, We have couple of stores around the town and all are on a t1 with ISDN for backup except for one on ISDN. Some t1 are shared for voice. We use t1 or ISDN to connect to the main store in order to communicate with the main server and get internet connection. Our internet is share with another company. We are currently using a cisco router and some are on some old gandalf bridge (need to take it out) to share connecting within stores. If a sub store's t1 goes down, it looses connection to private network, internet, and main server. The ISDN backup is there so that we can manually set to dial to SBC to get back into the private network. I am thinking of getting rid of the ISDN since it costs us around 30 bucks for just 1 ISDN bri interface if the T1 proves reliable and if there is a cheaper mean. I am looking at the DSL but i wonder it will be able to connect to our private network like how our current ISDN is setup. henry
-----Original Message-----
From: Henry Tang
Hi chris,
We have couple of stores around the town and all are on a t1 with ISDN for backup except for one on ISDN. Some t1 are shared for voice. We use t1 or ISDN to connect to the main store in order to communicate with the main server and get internet connection. Our internet is share with another company.
We are currently using a cisco router and some are on some old gandalf bridge (need to take it out) to share connecting within stores.
If a sub store's t1 goes down, it looses connection to private network, internet, and main server. The ISDN backup is there so that we can manually set to dial to SBC to get back into the private network.
I am thinking of getting rid of the ISDN since it costs us around 30 bucks for just 1 ISDN bri interface if the T1 proves reliable and if there is a cheaper mean. I am looking at the DSL but i wonder it will be able to connect to our private network like how our current ISDN is setup.
henry
We have several, over 15, offices connecting using DSL/cable and use VPN (Cisco 3005 main office, Cisco 3002 remote offices) and have very little downtime. I even have MRTG monitor the lines every 5 minutes. Ever get an email every 5 minutes non stop during an outage? This really is quite stable. We are going to be installing the above setup as backup connections for the frame/relay connections. DSL may not be cheaper than a single bri but the speed gain is well worth it. Ken
On Tue, 2004-02-10 at 16:53, Henry Tang wrote:
Hi,
I know this is not suse related, but i think someone here can answer my question concering a backup line for t1. I have a store and it needs to communicate with an outisde server and be on the net. I heard that a t1 is suppose to be up 99.9 percent of the time, so is it necessary to have a backup, maybe like an isdn? Has anyone experienced a t1 going down?
Many many times. You can end up with problems on the T1 or in the
equipment on either end. So they can and do go down.
Depending on your requirements and network architecture ISDN dial backup
can be used. Have set that up on a large number of sites along with
HSRP to protect against hardware failures at the end points.
But if you can afford to have that store out of communications for some
number of hours you may be able to get by without a backup circuit. It
really depends on the costs of being down verses the costs of having a
backup circuit plus the equipment plus the knowledge to set it up.
You may need to do a risk analysis to determine what is likely to fail
and the costs associated with such failures and the costs of providing
redundancy.
--
Scot L. Harris
tisdag 10 februari 2004 23:34 skrev Scot L. Harris:
But if you can afford to have that store out of communications for some number of hours you may be able to get by without a backup circuit. It really depends on the costs of being down verses the costs of having a backup circuit plus the equipment plus the knowledge to set it up.
You may need to do a risk analysis to determine what is likely to fail and the costs associated with such failures and the costs of providing redundancy.
I haven't done this myself, but from this there is one problem with the routing of it. You'd need a dynamic routing position, that could dynamically route information through a different line, in case your main line would be disrupted. As this is not the normal setup, of either T1 or xDSL, you'd need to set this up specifically with your end point. In which case, the rest is trivial, as it could be set up to work with any kind of secondary line, irrespective of that line's character. But always requires some sort of SLA with the end point of the service provider.
Henry Tang wrote:
Hi,
I know this is not suse related, but i think someone here can answer my question concering a backup line for t1. I have a store and it needs to communicate with an outisde server and be on the net. I heard that a t1 is suppose to be up 99.9 percent of the time, so is it necessary to have a backup, maybe like an isdn? Has anyone experienced a t1 going down?
Yes, but that was back in the days when I worked for a communications company and we had *MANY* DS1s (proper name for "T1"). A DS1 can be extremely reliable, as communications comanies aim for "five nines" reliability. Your SLA may provide for fall back circuits etc.
On Tue, 10 Feb 2004, James Knott wrote:
Henry Tang wrote:
Hi,
I know this is not suse related, but i think someone here can answer my question concering a backup line for t1. I have a store and it needs to communicate with an outisde server and be on the net. I heard that a t1 is suppose to be up 99.9 percent of the time, so is it necessary to have a backup, maybe like an isdn? Has anyone experienced a t1 going down?
Yes, but that was back in the days when I worked for a communications company and we had *MANY* DS1s (proper name for "T1"). A DS1 can be extremely reliable, as communications comanies aim for "five nines" reliability. Your SLA may provide for fall back circuits etc.
Sounds like it DS1s today are not as reliable. I know our main store has a fall back circuit and our providers monitors our DS1, but i wonder if my DS1 backup will do any good if it the problem wasn't cabling problem. So if the provider is dead, even a backup from them will not work, unless they use a differet carrier. henry
Henry Tang wrote:
On Tue, 10 Feb 2004, James Knott wrote:
Henry Tang wrote:
Hi,
I know this is not suse related, but i think someone here can answer my question concering a backup line for t1. I have a store and it needs to communicate with an outisde server and be on the net. I heard that a t1 is suppose to be up 99.9 percent of the time, so is it necessary to have a backup, maybe like an isdn? Has anyone experienced a t1 going down?
Yes, but that was back in the days when I worked for a communications company and we had *MANY* DS1s (proper name for "T1"). A DS1 can be extremely reliable, as communications comanies aim for "five nines" reliability. Your SLA may provide for fall back circuits etc.
Sounds like it DS1s today are not as reliable. I know our main store has a fall back circuit and our providers monitors our DS1, but i wonder if my DS1 backup will do any good if it the problem wasn't cabling problem. So if the provider is dead, even a backup from them will not work, unless they use a differet carrier.
That would depend on what you contracted for. If you want reliability, it costs more. For example, some of the systems I used to work on, had a fall back circuit, with automatic switching, should one of the service circuits fail. I have also worked on systems, with both fibre and microwave connections to the same site for redundancy or coming into two different areas of the building from two different directions, from two different COs and two different paths to the other end, to ensure reliablilty. However, that level of service costs money!
On Tue, 2004-02-10 at 18:04, Henry Tang wrote:
Sounds like it DS1s today are not as reliable. I know our main store has a fall back circuit and our providers monitors our DS1, but i wonder if my DS1 backup will do any good if it the problem wasn't cabling problem. So if the provider is dead, even a backup from them will not work, unless they use a differet carrier.
henry
Ah! The "I have redundant circuits to different providers, so why did
that guy with a backhoe take all of them out with one swipe?"
Redundancy can be very difficult. If you have full redundancy you will
have multiple circuits coming into the building at different points.
Unfortunately most buildings have a single demark and all your cables
will run in the same trench. One backhoe and everything goes dead.
Again, it will come down to an analysis of costs due to loss
connectivity verses costs to provide redundancy. As well as identifying
the most likely points of failures.
--
Scot L. Harris
Scot L. Harris wrote:
On Tue, 2004-02-10 at 18:04, Henry Tang wrote:
Sounds like it DS1s today are not as reliable. I know our main store has a fall back circuit and our providers monitors our DS1, but i wonder if my DS1 backup will do any good if it the problem wasn't cabling problem. So if the provider is dead, even a backup from them will not work, unless they use a differet carrier.
henry
Ah! The "I have redundant circuits to different providers, so why did that guy with a backhoe take all of them out with one swipe?"
Redundancy can be very difficult. If you have full redundancy you will have multiple circuits coming into the building at different points. Unfortunately most buildings have a single demark and all your cables will run in the same trench. One backhoe and everything goes dead.
Again, it will come down to an analysis of costs due to loss connectivity verses costs to provide redundancy. As well as identifying the most likely points of failures.
In another note, I mentioned where there were redunant paths. It was for a major bank and they not only had dual routes from my company, but also from the phone company. These circuits were used to link redundant computer centres. It would take some doing, to knock them off, with two sites and four independant routes between them.
-----Original Message-----
From: Henry Tang
Hi,
I know this is not suse related, but i think someone here can answer my question concering a backup line for t1. I have a store and it needs to communicate with an outisde server and be on the net. I heard that a t1 is suppose to be up 99.9 percent of the time, so is it necessary to have a backup, maybe like an isdn? Has anyone experienced a t1 going down?
YES, T1's can go down just like any other connection. A backup connection most likely will not be good if they are by the same provider. And you may not be able to actually get a second connection by another provider using there own coppper. In the U.S. a phone company usually has control over -all- of the copper in a geographic area. Ken
participants (6)
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Chris Purcell -
Henry Tang -
James Knott -
Ken Schneider -
Scot L. Harris -
Örn Hansen