Solved: Difference between SONET and GigE from Carrier?

davidhuynh5 · ‎01-15-2009

We have just provisioned a carrier to provide us with an OC12 (622mbps) connection. The carrier asked if I wanted a Sonet or GigE handoff? What does the carrier mean by this and is there a difference?

scottmac · ‎01-17-2009

It's not a limitation, it's providing the correct interface and signaling.

A copper cable with an RJ45-looking connector can have voice, any of several flavors of Ethernet, Token Ring, CDDI, T1, DDS56, ISDN ...

Optical is the same way; it can carry different types of signaling. The carrier is only asking your preference (so you can match it to whatever interface you have / desire).

IMO, GigE would be the better choice; it's a less expensive interface to buy (usually), and OC12 is going to max-out at 622Mbps.

You'll still get ~622 Mbps from the GigE, but you have some room to grow with just a little keyboard work (i.e., no new hardware required).

Good Luck

Scott

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Tom Randstrom · ‎01-16-2009

In the not too distant past, customers (like yourself) didn't have this option. The customer was required to purchase an expensive SONET (OC-n) interface card for their router to connect to the carrier's transport equipment.

With the GigE handoff option to the carrier, you can use a standard GigE router interface card (less expensive) to connect with the carrier's equipment. The carriers GigE interface will have a maximum throughput of 622Mbps, limited by the circuit size you purchased from the carrier. However, in the future, if you need additional bandwidth, you should be able to purchase additional bandwidth from the carrier (typically in 50Mbps increments), for this GigE interface; without changing out your router's interface card (sweet). If your router's interface was a SONET handoff and you needed more bandwidth, you would have to upgrade your router's interface card to an OC-48 (or possibly 2 x OC-12); quite an expensive proposition.

Hope this helps.

davidhuynh5 · ‎01-16-2009

Let me understand this correctly. So the limitation is my router interface card.

The carrier is still going to hand me a fiber connection to my router.

The carrier was also talking about framing differences between SONET and GigE?

Tom Randstrom · ‎01-16-2009

I'm not sure how to answer.

There are significant differences between the SONET and Ethernet technologies. They cannot be connected directly together over a fiber cable. Ethernet is a frame-based computer networking technologies for local area networks (LANs). SONET defines a technology for carrying many signals of different capacities through a synchronous, flexible, optical hierarchy. This is accomplished by means of a byte-interleaved multiplexing scheme.

My assumption on the carrier's side is their transport equipment can accept either a SONET or a GigE interface. He is giving you an option because he understands that to you may be more comfortable working with Ethernet than SONET and that GigE router interfaces are less expensive than SONET router interfaces. To the carrier, it is all just bits that need to be transported from A to B.

The router interface card your choose will take care of getting your data framed properly.

If you request a OC-12 SONET interface from the carrier, you will configure your router with an OC-12 interface. The router interface will take your data and add the SONET overhead/framing and couple it to the fiber to hand-off to the carrier.

If you request a GigE interface from the carrier, you will configure your router with a GigE interface. The router interface will take your data and package it into Ethernet frames and couple it to the fiber to hand-off to the carrier.

Any help?

scottmac · ‎01-17-2009

It's not a limitation, it's providing the correct interface and signaling.

A copper cable with an RJ45-looking connector can have voice, any of several flavors of Ethernet, Token Ring, CDDI, T1, DDS56, ISDN ...

Optical is the same way; it can carry different types of signaling. The carrier is only asking your preference (so you can match it to whatever interface you have / desire).

IMO, GigE would be the better choice; it's a less expensive interface to buy (usually), and OC12 is going to max-out at 622Mbps.

You'll still get ~622 Mbps from the GigE, but you have some room to grow with just a little keyboard work (i.e., no new hardware required).

Good Luck

Scott

seekhpar121 · ‎04-26-2009

I have cisco 3825 router and catalyst 3560 seitch,For GigE handoff option to the carrier which specific interface card is required for OC12 (622 mbps) connection.

Tom Randstrom · ‎04-27-2009

3825 router and 3560 switches do not support OC12 interfaces. You would need a 7300, 6500 or 7600 series router to be able to equip with an OC12 interface.

If you want to hand off a GigE interface to the carrier, the carrier will provide you the GigE interface requirements (fiber type and reach; SX, LX, etc.). Then you select the correct SFP/GBIC. You cannot interface directly to an OC12 connection with a GigE interface.