Determine the device is a router or switch given the Device IP via snmp

I Have a Linksys Managed Switch and a Cisco router

Using SNMP protocol I am trying determine the device is a router or switch and

Also which all layers are supported by the device?

Following methods are used .

Issue a get request for: "sysObjectId", "sysDescr", "sysServices", "ipForwarding".

Here is my problem I am surprised by the output of "sysServices"

For Cisco router sysServices = 78

For Cisco router ipForwarding = 1

For Linksys switch sysServices = 2

For Linksys switch ipForwarding = 2

For For windows workstation sysServices = 76

My Linksys Switch is a Layer 2 Device

Then value Should be 3 = 2^ (1-1) + 2 ^(2-1)

For Computing sysServices value blow stated Equation is used

Note: A value which indicates the set of services that this entity may potentially offer. The value is a sum. This sum initially takes the value zero. Then, for each layer, L, in the range 1 through 7, that this node performs transactions for, 2 raised to (L - 1) is added to the sum. For example, a node which performs only routing functions would have a value of 4 (2^(3-1)). In contrast, a node which is a host offering application services would have a value of 72 (2^(4-1) + 2^(7-1)). Note that in the context of the Internet suite of protocols, values should be calculated accordingly: layer functionality

1 physical (e.g., repeaters)
2 datalink/subnetwork (e.g., bridges)
3 internet (e.g., supports the IP)
4 end-to-end (e.g., supports the TCP)
7 applications (e.g., supports the SMTP) For systems including OSI protocols, layers 5 and 6 may also be counted.

1.What are Possible values for sysServices ? How the sysServices value computed by the vendors?

Thanks in advance