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sg2006
Intermediate
Joined: June 01 2006
Location: United States
Posts: 2
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| Posted: June 01 2006 at 10:07am | IP Logged
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I am currently investigating SIP servers to see if they will work within our enterprise. The initial phase of the project if we find a server that will work for us is to reduce toll cost between facilities in the US and China. Reduce the cost of call between facilities but since there is a 12 hours time difference we have people with home offices that need to call back to the States or from the States to vendors or facilities in China.
Looking for a solution that allows us to use SIP hard or softphones and the possibility of locating SIP servers at locations in China and the US.
We have an Avaya IP enabled PBX here and use Centrex lines at the facilites in China - if we can connect these to the SIP server that is a plus.
Will your product allow us to do what we want?
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support
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Joined: January 26 2005
Location: United States
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| Posted: June 01 2006 at 11:11am | IP Logged
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We have attempted to isolate the elements of your post:
1) The initial phase of the project if we find a server that will work for us is to reduce toll cost between facilities in the US and China.
Your stated goal is one of the main reasons why we have developed this software.
2) We have people with home offices that need to call back to the States or from the States to vendors or facilities in China.
VOIP calling between the States and China is not a problem. Quality of service (Qos) is a function of your interconnecting ISPs. Remote home office VOIP users (using desktop IP phones or softphones on a PC/laptop) are handled the same way as users at your office. Remotely located home users can access the system the same way as office personnel.
3) Looking for a solution that allows us to use SIP hard or softphones and the possibility of locating SIP servers at locations in China and the US.
There are various options here depending on the size of deployment and complexity you want to manage. Let’s look at a few simple examples:
Single VOIP Domain:
You want to connect one office in China with one office here in the States. You can deploy a single Centrex Proxy Server and VOIP Media Proxy at your office in the US. All user phones (regardless of physical location) will be set up (provisioned) such that they all access the single VOIP domain in the States. Now all users can call each other via the network (Internet) using SIP/RTP. This single VOIP domain model can be used to connect all your users if you want. It can be scaled and can grow as your user base grows (SIP and Media).
Single Logical VOIP Domain – Multiple Proxies:
You want to connect one office in China having its own VOIP domain with one office here in the States having its own VOIP domain. You can deploy a single Centrex Proxy Server and VOIP Media Proxy at your office in the US and you can deploy a single Centrex Proxy Server and VOIP Media Proxy at your office in China. All users in China will register with the VOIP domain in China. All users in the States will register with the VOIP domain in the States.
The two physical VOIP domains (the China domain and the US domain) can logically be tied together as one. To do this, you also deploy a database server of your choice (i.e. MySQL, etc) to allow the two Centrex Proxy Servers to access the same registrar database. If you deploy this way, you now have one large logical VOIP domain using two separate physical domains. It equates to having one big VOIP phone system using multiple proxies. This has great advantage for SIP end user devices. Most IP desktop phones force the user to key in long arduous entries for SIP addresses (URIs) that are not in the immediate domain. Using the “logical VOIP domain model”, users can simply dial the desired unique extension of the person to call without need for knowing the exact registered VOIP domain. The Centrex Proxies handle this transparently. Also, if disjoint office locations are physically very far apart, it is a good idea to session and media proxy each location. That way, VOIP domain users in China will not have their media proxied by media proxies that are half way around the world (in the States). This deployment can be scaled and can grow as your user base grows (SIP and Media).
4) We have an Avaya IP enabled PBX here and use Centrex lines at the facilities in China - if we can connect these to the SIP server that is a plus.
If you can vector calls from the Avaya IP switch to the Centrex Proxy Server (via call routing or dial plans), the Centrex Proxy Server will be able route the call to the destination extension (in China, the States, etc). We will need more info for your specific situation.
5) Will your product allow us to do what we want?
We think so. What you have described is exactly why these products were developed. To give VOIP end users the ability to deploy their own VOIP systems without the need for service providers.
Repost as needed,
Support
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sg2006
Intermediate
Joined: June 01 2006
Location: United States
Posts: 2
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| Posted: June 01 2006 at 11:49am | IP Logged
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Thanks for the reply.
I will try and address some of the issues that you brought up using the same points.
1. I agree and that is why we are investigating the various SIP offerings out there.
2. In some of the trials that we have conducted the latency for some of the home users in China back to the US servers has been 350ms or more. That is one reason we are looking at having servers in each country or region of the world. We have a Sprintlink circuit between China and US locations with a 200ms latency and with our Cisco routers we should be able to provide QOS between the facilities.
3. Not sure how we would set this up but may be the 2 proxies would be best. We have multiple locations within China that may be using this. Our preferred database is Oracle - will that be a problem?
4. I think we can handle the trunking but as you mentioned we will need to discuss further.
5. How do we proceed? Do you work through dealers or direct with us.
6. I have another question - where withing our network are the servers located - behind our firewall or in front of the firewall?
I have proposals from some vendors that have servers located outside and inside.
Thanks
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support
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Joined: January 26 2005
Location: United States
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| Posted: June 01 2006 at 1:33pm | IP Logged
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Item 2: In some of the trials that we have conducted the latency for some of the home users in China back to the US servers has been 350ms or more. That is one reason we are looking at having servers in each country or region of the world. We have a Sprintlink circuit between China and US locations with a 200ms latency and with our Cisco routers we should be able to provide QOS between the facilities.
Understood. Very good.
Item 3: Not sure how we would set this up but may be the 2 proxies would be best. We have multiple locations within China that may be using this. Our preferred database is Oracle - will that be a problem?
SG, sounds like multiple Centrex Proxies (with associated VOIP media proxies) at each widely dispersed geographical location would be best. That way, each “local” domain would have the lowest latency regarding SIP and most importantly regarding the RTP voice streams for local calling. Remember, the Centrex Proxy Servers have the ability to share a common registrar database and thus make individual domains appear as one large logical domain.
Using an Oracle registrar database: It is not a problem as long as there are ODBC drivers available for Oracle that can be installed on the proxy’s host machine. We did a quick check and found that there are ODBC drivers available for Oracle. You can review this URL:
Oracle ODBC Connectivity FAQ
Item 4: I think we can handle the trunking but as you mentioned we will need to discuss further.
Agreed.
Item 5: How do we proceed? Do you work through dealers or direct with us.
LanScape will work directly with your company. Our support group will be the interface between you and us and if things get sticky. In addition, our support personnel have direct access to our development team if required.
To start out, you can visit the LanScape web site and start requesting trial images of the products. Go to the “VOIP Test Drive” area off of the home page. There is additional info there. As you progress through your evaluation, you can post additional pre-sales related questions to this forum.
Item 6: I have another question - where within our network are the servers located - behind our firewall or in front of the firewall? I have proposals from some vendors that have servers located outside and inside.
The deployment location of the servers is your choice. The Centrex Proxy (SIP proxy) and the VOIP Media Proxy (RTP media proxy) can be deployed in the global address space or in your private network behind your outermost firewall or router. At our LanScape facility, we have them deployed behind our outermost router for added (NAT) security.
One additional item: If you plan to deploy using Oracle as a common registrar database, you will also be able to share a common user authentication database using the same ODBC connectivity. This way, you can provision the user names (extensions) and challenge handshake passwords from a single database. It makes managing user accounts easier. How you manage (edit, change, delete) records in your Oracle authentication database is up to you.
Repost as needed,
Support
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LanScape Support Forum -> SIP Proxy and Media Proxy - Pre-Sales Technical Support
Topic: Enterprise SIP
