Shell variable is not working

One of my shell script, I'm using shell variable to substitute parameter value to a oracle related command "tnsping". without substitution same value is working fine. see below example.

Below is the result is expected with command:

> tnsping "(ADDRESS = (PROTOCOL = TCP)(HOST = uedcb031)(PORT = 1521))"

TNS Ping Utility for IBM/AIX RISC System/6000: Version 11.2.0.3.0 - Production on 01-NOV-2012 19:28:42

Copyright (c) 1997, 2011, Oracle. All rights reserved.

Attempting to contact (ADDRESS = (PROTOCOL = TCP)(HOST = uedcb031)(PORT = 1521))
OK (0 msec)



my shell variable have below value

> echo $p
"(ADDRESS = (PROTOCOL = TCP)(HOST = uedcb031)(PORT = 1521))"

When I'm executing tnsping command with same variable, I'm not getting same result:
> tnsping $p

TNS Ping Utility for IBM/AIX RISC System/6000: Version 11.2.0.3.0 - Production on 01-NOV-2012 19:28:25

Copyright (c) 1997, 2011, Oracle. All rights reserved.

Used parameter files:
/oracle/product/11.2/network/admin/sqlnet.ora

TNS-03505: Failed to resolve name

Can you please tell me how to correct this or if I'm wrong somewhere.